BMT AbstractsInternational Maritime TechnologyVolume 70 Number 10 October 2015

Abstract Numbers : 2015102251 – 2015102500

ISSN 2051-7793

BMT ABSTRACTS

Volume 70, Number 10, October 2015 Abstracts 2015102251-2015102500

Compiled and Edited by: Gillian Smith Information Services BMT Group Limited Goodrich House 1 Waldegrave Road Teddington Middlesex TW11 8LZ U.K. Tel: 07909991180 Email: gilliansmith@bmtmail.com

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Abstracts 2015102251-2015102500 Volume 70 – No 10 – October 2015

CONTENTS

Page No.

1. DESIGN AND CONSTRUCTION

1.1 Ship/structure description 837 1.2 Design 841 1.3 Shipbuilding technology/constructional techniques 849

2. OPERATION

2.1 Power sources and fuels 850 2.2 Equipment and installations 853 2.3 Maintenance, repair and conversion 854 2.4 Cargoes and cargo handling 856 2.5 Ports and waterways 857 2.6 Coastal/offshore engineering and marine renewable energy 858 2.7 Safety at sea 871 2.8 Environmental protection 874 2.9 General operation 875

3. FLUID MECHANICS

3.1 General hydrodynamics, hydraulics and oceanography 880 3.2 Resistance and propulsive performance 881 3.3 Motion, seakeeping and manoeuvring 888 3.4 Fluid structure interaction 902 3.5 Aerodynamics and wind engineering 914

4. STRUCTURES AND MATERIALS

4.1 Structural response 915 4.2 Properties of materials 929 4.3 Corrosion and fouling 932

5. NAVAL VESSELS AND DEFENCE TECHNOLOGY 932 6. MISCELLANEOUS 935

AUTHOR INDEX A-1 SHIP AND STRUCTURE INDEX S-1 KEYWORD INDEX K-1

ABSTRACTS 837

1.1 SHIP/STRUCTURE DESCRIPTION

2015102251

CDC Heron: a one-man army. Offshore Marine Technology, 2nd Quarter 2015, p 8 [3 p, 3 fig] http://www.rina.org.uk/omt.html No author given English

Celtic Design Consultants (CDC) have conceptualised, and owns the design patent for, the CDC Heron class, a dynamic positioning 2 (DP2)-equipped double-decker jack-up barge design. When it comes to oil and gas-related missions, the vessel is intended to be used in offshore operations including: well completions, testing and servicing; enhanced oil recovery; slim hole drilling; plug and abandon tasks; and well decommissioning. Alternatively, the CDC Heron could be deployed by renewable energy sector players, being equally suited to wind farm-related work. For instance, the barge can provide a stable, walk-to-work platform for turbine technicians, assist with cable installation and serve as a mother ship for daughter craft. A general arrangement drawing is included in this article.

Barges Jackup platforms Vessel descriptions

2015102252

Going to town on the Kabina class. Offshore Marine Technology, 2nd Quarter 2015, p 15 [3 p, 3 fig] http://www.rina.org.uk/omt.html No author given English

Monaco-based McFarlane ShipDesign has unveiled its proposed Kabina class of eight-deck offshore accommodation barge. The Kabina class comes in two pre-made sizes, the 500 and 600, but both are customisable because there is a large emphasis on flexibility of design and the ability to mould the vessel to each client’s particular needs. The basic arrangement for either Kabina size envisions a 130m x 32.2m x 8m vessel, featuring a 2,400tonne steel hull and a steel superstructure weighing between 1,000-1,200tonnes. Gross tonnage would be approximately 18,000tonnes for the 500 model and 19,000tonnes for the 600. The vessel’s ideal power arrangement comprises four medium-speed diesel generators (two rated 1,500kW, the other pair rated 750kW, apiece) and a 300kW emergency generator. A flexible approach towards fuel types means that the Kabina

can be configured to burn MDO, HFO or biofuels. There is also the possibility for LNG tanks to be installed on future versions of the class. A general arrangement drawing is included in this article.

Accommodation spaces Barges Vessel descriptions

2015102253

Versatile vessel addresses deepwater challenges. The Motor Ship, v 96 n 1127, June 2015, p 26 [2 p, 2 fig] http://www.motorship.com/ Tinsley, D. English

This article describes CEONA AMAZON, a multi-function tie-back, field development and construction vessel capable of executing all aspects of deepwater projects in environmentally-challenging locations for keener logistic costs. Based on a drillship hull design, and with main dimensions of 199.4m x 32.2m, the CEONA AMAZON offers the capability for operating in multiple pipelay modes, and incorporates heavy-lift facilities and substantial underdeck and above deck carrying capacity. The hull of the vessel was assembled at Crist's Gdynia facility in Poland and the outfitting was done at Lloyd Werft Bremerhaven, Germany. The innovative G-lay pipe lay system, developed and patented by the vessel’s owner Ceona Services, features an inclinable lay spread with a top tension of 600te and a rigid firing line system. Rendering the vessel akin to a ‘floating factory’, in-situ assembly of rigid pipe joints is carried out along a traditional firing line. Once welded, the pipe is deflected around an 18m-diameter stern wheel and led up to the pipelay tower, culminating in vertical exit, in J-lay fashion, through the moonpool in bottom of the hull amidships.

Heavy lift vessels Pipelaying vessels Vessel descriptions

2015102254

Stena sets new benchmark in tanker design. The Motor Ship, v 96 n 1127, June 2015, p 44 [2 p, 2 fig] http://www.motorship.com/ Tinsley, D. English

Giving first form to the IMOIIMAX class of chemical/product carrier, the 49,800dwt STENA IMPRESSION leads a US$400m series of ten

838 ABSTRACTS

newbuilds from Guangzhou Shipyard International (GSI) in China. The new breed has been conceived for the transport of vegetable oils, chemicals, and clean and dirty petroleum products, embodying parcel tanker-type capabilities that give increased scope for payload permutations and individual consignment sizes. Protected by the mandatory double hull construction, the cargo section is divided by a centreline bulkhead and transverse bulkheads into nine pairs of tanks of an aggregate 54,000m3. The 16 cargo tanks and two slop tanks are uniform in size at 3,000m3, the filling restriction for tanks carrying IMO Type 2 products. Moreover, all tanks are designed to take any of the Type 2, Type 3 and petroleum products for which the vessel has been developed.

Chemical tankers Products tankers Vessel descriptions

2015102255

ANDALUCIAN ZEPHYR: first high bulk 34E design. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 4 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

Namura Shipbuilding Co., Ltd., Japan, delivered the ANDALUCIAN ZEPHYR, a 34,436DWT bulk carrier, to Three Kings Shipping Corp. Inc. on 12 March, 2014. This is the first vessel of the series of 34,000DWT type bulk carriers called High Bulk 34E, which has been developed in collaboration with one of the Namura group companies, The Hakodate Dock Co., Ltd., as a successor of the Hakodate Super Handy 32 with a good reputation in the handy size bulk carrier market, and the specifications have drastically been reviewed and modified from the predecessor to respond to the needs of today’s market. The vessel is designed for carriage of grain, coal, steel products, and logs/lumber as a bulk carrier, and the shallower draft hull form is designed in maximizing the loading capacity. A general arrangement drawing is included in this article.

Bulk carriers Vessel descriptions

2015102256

ASIA VISION: LNG carrier for Chevron. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 8 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

This article describes ASIA VISION, the first in a series of six LNG carriers being constructed by Samsung Heavy Industries in South Korea, for US-based Chevron. ASIA VISION’s four centre cargo tanks have a total capacity of 160,000 m3. A general arrangement drawing is given.

LNG carriers Vessel descriptions

2015102257

ATLANTIC GAS 22,000m3 LPG/Ammonia/VCM carrier. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 12 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

ATLANTIC GAS is the first vessel in a series of six for Chilean shipowner Ultragas. The vessel was delivered to the owner in September 2014 from STX Offshore & Shipbuilding, Korea. ATLANTIC GAS is an LPG carrier type 2G for the handling and transportation of refrigerated liquefied gases. The cargo system features four cargo tanks, seven pairs of topside and double bottom water ballast tanks, and two pairs of heavy fuel tanks. A general arrangement drawing is included in this article.

LPG carriers Vessel descriptions

2015102258

BALT FLOT 1: latest double cargo vessel design. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 16 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

BALT FLOT 1 is the first in a series of the new RST54 design from the Marine Engineering Bureau,

ABSTRACTS 839

Russia. The river-sea going wet and dry cargo vessel was built by JSC Okskaya Sudoverf for the BF Tanker company. BALT FLOT 1 has a length overall of 140.85m, breadth of 16.60m and depth 6.00m and comes under the Volga-Don max class. A general arrangement drawing is included in this article.

Cargo ships Oceangoing river vessels Vessel descriptions

2015102259

BERKARAR: ro-pax for Turkmenistan. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 20 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

BERKARAR is the first of two ro-pax ferries constructed by Uljanik Shipyard for the State Service of Maritime and River Transportation of Turkmenistan. The vessel is intended for the transportation of passengers, trucks and other vehicles on the Caspian Sea. BERKARAR is 155.8m in length, 17.5 meters wide and can transport 200 passengers and 54 trucks on two closed decks. A general arrangement drawing is included in this article.

Ferries Ro/ro ships Vessel descriptions

2015102260

BURGAN: optimised product/chemical tanker. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 22 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

This article, which includes a general arrangement drawing, describes BURGAN, the first in a series of four eco-friendly product/chemical tanker from Hyundai Mipo Dockyards, Korea for Kuwait Oil Tanker Co. The 38,000dwt double hull vessel has been fitted with a Hyundai-Wärtsilä 7RT-flex50-D

that has an MCR output of 8,900kW x 99rpm and meets with the IMO Tier II emission reduction regulations.

Chemical tankers Products tankers Vessel descriptions

2015102261

CASCADE: first Emerald 39,000dwt bulk carrier. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 24 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

CASCADE is the first in the series of the Emerald 39,000dwt bulk carrier designs that was developed by Bestway Marine Engineering Design. The vessel was constructed by Jiangmen Nanyang Ship Engineering, China and delivered to its owner in June 2014. The design of the Emerald bulk carrier came from the need to develop eco-friendly vessels to meet with the needs of future environmental regulations. A general arrangement drawing is included in this article.

Bulk carriers Vessel descriptions

2015102262

CCNI IQUIQUE: next generation 6,800TEU container ship. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 26 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

CCNI IQUIQUE is the first vessel of HHIC’s second generation of 6,800TEU class container carriers which was constructed at HHIC-Phil for Paxi Maritime Corporation. A reduction of about 7% in fuel consumption by the main engine at NCR power has been achieved through the use of the Wärtsilä 7RT-flex82T-B that has been delta tuned and complies with the IMO Tier II NOx emissions standards. A general arrangement drawing is included in this article.

Containerships Vessel descriptions

840 ABSTRACTS

2015102263

CEONA AMAZON: pipelaying vessel from Lloyd Werft. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 28 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

This article describes CEONA AMAZON, a multifunctional pipelay and construction vessel built by Lloyd Werft, Germany for Ceona. The article includes a list of technical particulars and a general arrangement drawing. See also abstract numbers 2015061378 and 2015071511.

Pipelaying vessels Vessel descriptions

2015102264

CHARLOTTE SCHULTE: wide-beam boxship. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 30 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

CHARLOTTE SCHULTE is the first vessel in a series of five 5,400TEU containerships that are being constructed at HHIC-Phil for German shipowner Bernhard Schulte. The vessel has a 37.30m beam for the expected new expanded Panama Canal and has a 22m depth with a scantling draught of 13.90m, and weighs in at 65,000dwt. A general arrangement drawing is included in this article.

Containerships Vessel descriptions

2015102265

COPIAPO: LNG carrier with DSME “shield type structure”. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 32 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

COPIAPO is the first in the series of two of the latest optimised design of container vessel for Compania Sud American de Vapores, Chile, which was

delivered by Samsung Heavy Industries, Korea at the end of 2014. COPIAPO is an environmentally friendly design with an optimised hull form for providing better performance and meets with the IMO’s Energy Efficiency Design Index (EEDI) standards. For this the vessel achieved a 33% reduction in its EEDI rating and so meets with phase 3 of the regulation (30% reduction in year 2030) without any future modification. A general arrangement drawing is included in this article.

Containerships Vessel descriptions

2015102266

CORCOVADO LNG: gas carrier with DSME “shield type structure”. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 34 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

CORCOVADO LNG is the latest 159,800m3 LNG carrier for TMS Cardiff that utilises the Daewoo Shipbuilding & Marine Engineering cargo containment structure that it calls its “shield type structure”. The “shield type structure” allows a maximum pressure inside the cargo tank of up to 7bar, which enables it to store more LNG safely over conventional carriers. A general arrangement drawing is included in this article.

LNG carriers Vessel descriptions

2015102267

COSTA DIADEMA: new class of cruise ship from Fincantieri. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 36 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

This article gives a list of the principal particulars of the 11,247dwt cruise ship COSTA DIADEMA, a

ABSTRACTS 841

general arrangement drawing is also given. See also abstract number 2015051007.

Cruise ships Vessel descriptions

2015102268

CRYSTAL STAR: Panamax bulk carrier from Sanoyas. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 38 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

Sanoyas Shipbuilding Corporation delivered the Panamax bulk carrier, CRYSTAL STAR to Southern Route Maritime, S.A. in June 2014. The vessel is the first of a series of newly developed 82,000DWT type Panamax bulk carriers. The vessel has larger cargo hold capacity and further improved fuel consumption by 10% compared with the previous version of 83,000DWT type featuring 10% improvement in fuel efficiency from the existing design. A general arrangement drawing is included in this article.

Bulk carriers Vessel descriptions

2015102269

CSCL GLOBE: 19,000TEU containership from HHI. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 40 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

This article describes CSCL GLOBE, the first of five identical container ships to be built at the Hyundai Heavy Industries shipyard in Ulsan, South Korea, for Shanghai-based China Shipping Container Lines (CSCL). CSCL GLOBE has a length of 400m, width of 58.6m and a depth of 30.5m. It has a deadweight of 184,320t and a cargo handling capacity of 187,541t. A general arrangement drawing is given.

Containerships Vessel descriptions

2015102270

DEEPWATER ASGARD: 12000 type drillship. Significant Ships of 2014. Published by RINA, London, UK, 2015. ISBN 978-1-909024-31-1. CD-ROM. P 42 [2 p, 2 fig] http://www.rina.org.uk/sigships.html No author given English

DEEPWATER ASGARD is a Daewoo Shipbuilding DSME 12000 design, dynamically positioned drillship. The ship is capable of drilling to a depth of 10,668 m and able to operate in moderate environments and water depths up to 3,048 m. A general arrangement drawing is included in this article.

Drillships Vessel descriptions

1.2 DESIGN

2015102271

Small catamarans: design approaches and case studies. RINA Transactions - International Journal of Small Craft Technology, v 157 Part B1, January-June 2015 http://www.rina.org.uk/ijsct.html Nazarov, A. English

The paper presents the review of design experience and applied research of catamaran craft, up to 30m in length, of total over 30 catamaran designs, developed by ‘Albatross Marine Design’ and launched during recent years. Architecture of catamarans is discussed; typical catamaran hull shapes are reviewed and their suitability for different applications and desired speeds are studied. Recommendations are given for hull shape particulars selection. Performance issues are studied using available theoretical methods and sea-trials data of number catamarans. Components of resistance of catamarans and methods of their prediction are reviewed. Comparison of methods is presented and samples of their applications for hull shape selection are shown. Seakeeping performance is discussed in terms of vertical accelerations. Results of full-scale measurements of vertical accelerations on number of craft are presented. Controllability discussion is based on turning track measurements for power catamarans of different configurations at different speeds. Structural design issues are reviewed with special interest in composite craft and their improvements. Perspective applications of catamaran

842 ABSTRACTS

concept for different types of craft are indicated. Presented are samples of catamaran designs for special, small commercial and pleasure catamarans.

Catamarans Ship design

2015102272

LNG tank 'fender' takes vessel design beyond B/5. The Naval Architect, June 2015, p 30 [5 p, 5 ref, 1 tab, 9 fig] http://www.rina.org.uk/tna.html Vredeveldt, A.W., Hoogeland, M.G. English

LNG is recognised as a viable fuel for ships, which will contribute significantly to a reduction of pollutant emissions, most notably SOx and particulate matter. The most convenient storage of the fuel is as a liquid, which implies storage at cryogenic temperatures. This is currently done in cylindrical double walled pressurised tanks, with the annular space vacuumed. This shape is not easy to fit in a ship design. Moreover up-coming IMO regulations require a minimum safe distance between LNG tanks and the ship’s shell, which further restricts the naval architect’s design space. The idea described in this article is a first principles approach, towards tank placement, providing more design freedom without compromising safety, or even improving safety.

Collision resistance LNG tanks Position (location) Ship design

2015102273

Growing length in the megayacht industry and structure-related design topics. Ships and Offshore Structures, v 10 n 3, June 2015, pp 221-231 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.870775#.VYfGAE3JCUk Ivaldi, A. English

The demand for increasing the size of pleasure crafts has led those vessels to reach, in recent years, the biggest dimensions ever seen, typical of small- to medium-sized passenger vessels. Recently, some yachts were even classified as passenger vessels instead of pleasure crafts. However, this demand for growing dimension remains strictly linked to the design issues typical of a yacht (large glass surfaces, big openings in the shell due to the presence of shell

doors, very irregular general arrangements with big unsupported spaces, etc.) and forces the structural designer to pay a deep and continuous attention to the structural details as well as to find every possible way to guarantee the structural continuity in both vertical and longitudinal directions. This article, after a brief introduction on the actual market trend in the yacht industry, goes through the main stages of the structural design highlighting its peculiarities and the principal differences with the design of other kinds of ships. An up-to-date situation of the classification rules about big-sized yachts is also presented together with an analysis of how the classification bodies are responding to this rather new market. A short review on other design issues typical of yachts like corrosion protection and construction tolerances closes this work.

Motor yachts Ship design Superstructures

2015102274

Structural design of passenger cruise ships – an introduction to classification requirements. Ships and Offshore Structures, v 10 n 3, June 2015, pp 232-238 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.913759#.VYfPz03JCUk Bajic, D. English

Modern passenger cruise ships are also from structural point of view very complex objects that vary very much from one design to another. Hence assessment of such a kind of ship is difficult if not impossible to do only by application of conventional rule formulas since they are usually developed and suitable to apply on similar structural arrangements. Therefore assessment of modern passenger cruise ships has to be done combining applicable rule formulas with extensive use of various types of direct calculations. A brief introduction on structural design assessment procedures as foreseen by Lloyd's Register Ship Rules is described in the paper.

Classification society rules Cruise ships Design criteria Ship design

ABSTRACTS 843

2015102275

Equivalent shell element for ship structural design. Ships and Offshore Structures, v 10 n 3, June 2015, pp 239-255 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.819689#.VYfQiE3JCUk Avi, E., Lillemäe, I., Et al English

This paper presents an equivalent shell element for assessing the ship global and local static and vibration response in early design phases. The element provides a computationally economic tool for global analysis and the same mesh can be used in primary, secondary and tertiary level. The stiffened panel is considered as a three layer laminate element, where the first layer represents the plate, the second layer represents the stiffener web and the third layer represents the stiffener flange. The layers are described as 2D iso- and orthotropic materials, where elasticity matrices are found by applying the rule of mixtures. The element includes the in-plane, membrane-bending coupling, bending and additionally also shear stiffness, which follows the Reissner-Mindlin plate theory for anisotropic homogenous shells. The local plate bending response between the stiffeners is considered as well. The developed shell formulation has been implemented in commercial FE software FEMAP with NX Nastran and demonstrated through two case studies. Results are validated against 3D fine mesh quasi-static and vibration analyses and very good agreement is observed.

Passenger ships Ship design Structural analysis Vibration analysis

2015102276

On the shear lag effective breadth concept for composite hull structures. Ships and Offshore Structures, v 10 n 3, June 2015, pp 272-289 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.887172 Ghelardi, S., Gaiotti, M., Rizzo, C.M. English

The aim of this paper is to study the concept of shear lag effective breadth of plating, widely applied in the scantling assessments of metallic ship structures, for the special case of composite hull stiffened plating. Indeed, geometries and material behaviour are rather

different and the definition of the effective breadth is worthy of investigation. A broad literature survey highlighted that the case of composites is almost not covered by previous studies and that only simplified empirical formulations are proposed for effective breadth evaluations in the rules of classification societies. Thus, suitable finite element models were created and validated to investigate the behaviour of the effective breadth of stiffened laminates when varying geometrical and other typical parameters of composite made ship structures. It was found useful to switch from stresses to strains in the effective breadth definition, considering the anisotropy of the material. An extensive sensitivity analysis allowed assessing the effect of parameters governing the phenomenon. Eventually, regression formulae are proposed summarising the outcomes and possibly applicable in design scantling practice.

Composite materials Effective width Finite element method Stiffened plates

2015102277

CFD tools and adapted methodologies for marine and offshore engineering projects. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25939 [23 p] https://www.onepetro.org/conference-paper/OTC-25939-MS Thilleul, O., Drouet, A., Et al English

Computational Fluid Dynamics (CFD) tools have progressed greatly in the past decades in such a manner that they have become a recurring tool during the workflow of an engineering project. In the specific case of Marine and Offshore Engineering, these tools are more and more used to predict forces on structures with a very detailed level of precision, to optimise hull forms to conceive more efficient and environmentally friendly designs and also to reassure structural engineers with respect to the assumptions made during complex engineering problems. In this paper several examples of how these tools and methodologies have been employed in the design process of Marine and Offshore structures are presented. Validations compared to tank tests and wind tunnels are presented for damping coefficients, green water impact, aerodynamic coefficients and non-linear wave loading studies. Throughout these examples it is shown how the need of dedicated tools/methodologies is necessary in order to

844 ABSTRACTS

efficiently use the CFD tools during the Naval and Offshore design process. Very often, distinct phenomena need to be modeled in order to correctly apprehend the complexity of the flows. To do so, coupling distinct approaches is sometimes necessary: CFD solver to a potential one for instance. In the paragraphs below four examples are illustrated: nonlinear wave loading computations, damping coefficients computation, aerodynamics wind loads estimation on complex topside structures, and prediction of green water impact on a FPSO.

Computational fluid dynamics Design process Marine engineering Offshore engineering

2015102278

CFD-based numerical wave basin for offshore floater design. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26060 [19 p] https://www.onepetro.org/conference-paper/OTC-26060-MS Kim, J.W., Jang, H., Et al English

Technip recently has developed new cost-effective and riser-friendly Semi-submersible hull forms adapted to various operation sites, with considerable saves in design cost and time. This achievement is greatly in debt to Technip's numerical wave basin, which has been developed and validated through previous projects and collaborative R&D efforts with clients. Validation of the numerical wave basin against the model test and full-scale measurement data has proven that the numerical wave basin can provide more realistic and reliable prediction of the wave- and vortex-induced motion than the physical model test. The validated numerical wave basin has been applied to develop a new semi-submersible hull design for a given design environment, partially replacing the role of the physical model test in the traditional design spiral. The new design spiral based on numerical wave basin provides optimised hull

design more expeditiously and efficiently than the traditional design spiral based on physical model test. Review of the development, current status and future prospects of numerical wave basin for offshore platform design is presented in this paper.

Computational fluid dynamics Numerical models Platform design Semisubmersibles Wave models

2015102279

Gulfstar - naval architecture from design to hull installation. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26052 [39 p] https://www.onepetro.org/conference-paper/OTC-26052-MS Antony, A., Park, Y-C., Et al English

Williams Field Services use of the classic Spar hull form for the deepwater field development projects is the first classic Spar hull since ExxonMobil installed the Diana/Hoover Spar in 2000. Since that time, 14 Truss Spars and one Cell Spar have been installed. Learnings from those Spars along with increases in the metocean condition since 2000, significant increases in topside payload during detailed design, support of the five initial SCRs on a porch at the keel plus the decision to fabricate the hull in a US graving dock provided new challenges for the Naval Architects from design through to hull installation. The paper discusses the key drivers, constraints and criteria that had to be reconciled into a floating system with acceptable global motions, acceptable horizontal trim and robust characteristics for changes in topside payload and CGs. Examples of these sometimes conflicting design requirements include: the increased hull freeboard which was driven by the new metocean condition which then led to a higher topside VCG, a 30% increase in the topside's maximum operating payload between the end of FEED and midway into final design yet the depth and length of the graving dock dictated that these changes had to be accommodated without increasing either the

ABSTRACTS 845

diameter or draft of the hull. This paper presents the challenging results of the model tests and their impacts on the design of the mooring system as well as the very close tolerances in trim and stability for the tow out of the graving dock and then to site.

Offshore platforms Platform design

2015102280

Gulfstar - structural design of the classic spar hull for improved constructability. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26008 [30 p] https://www.onepetro.org/conference-paper/OTC-26008-MS Poll, P., Park, Y.C., Et al English

Historically, Spar hulls have been compartmented using both flats and radial bulkheads. These hulls were fabricated into quarter or half sections and joined into full cylinder sections then into the full hull length while in a horizontal orientation. This approach left considerable fabrication work to be performed after assembly, disadvantageously, due to the horizontal position. The configuration of the Gulfstar FPS reduces the number of radial bulkheads by locating the flats closer together, thus opening up the option to fabricate full cylindrical sections upright with open tops for ventilation and access during fabrication. Rotating each cylindrical section for final assembly was not required until all possible work, inside and out, on each section had been completed. This fabrication plan leaves only structural and systems tie-ins between sections once blocks are rotated and set in place. Vertical fabrication of sections starts an overall structural arrangement philosophy to develop a configuration that is not only repetitive and efficient but also “fabrication friendly.” The idea for improving constructability permeated other aspects of structural design. The purpose of this paper is to summarize some of the ways in which the Spar structure was arranged to improve fabrication and to evaluate the expected improvement with actual fabrication experience. This paper presents the genesis of the basic framing then culls out and discusses some notable lessons learned. The information and results presented in this paper are applicable to engineers, designers and fabricators when evaluating structural arrangements and fabrication options for stiffened plate hulls,

particularly Spar hulls. Cost and schedule benefits can potentially be achieved by incorporating some of the lessons learned presented in this paper.

Fabrication Offshore platforms Platform design

2015102281

Features architecture of mean ship to navigation in heavy, stormy and ice conditions on the Northern Seas. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 2, p 47 [11 p, 7 ref, 8 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Khramushin, V. English

These studies of storm seaworthiness are most relevant for vessels with a mean displacement, for which the length and height of storm waves are comparable with the main dimensions of a marine vessel. As an analytical tools is activated synthesis of good seamanship technical experience and new engineering justification to build outside appearance (ship's architecture) and the main elements of the hull shape, which directly affect the seaworthiness of the ship maneuvering and conditions in difficult, storm and ice conditions for the navigation.

Hull form Ice conditions Seakeeping Ship design

2015102282

Structural design and optimisation of an aluminium trimaran. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 62 [9 p, 14 ref, 17 tab,15 fig] https://www.crcpress.com/product/isbn/9781138027893 Fuentes, S., Salas, M., Et al English

The structural analysis of multihulls is relatively complex due to the bridge connecting the hulls; this structure introduces additional stresses to those

846 ABSTRACTS

typical of a monohull. The aluminium trimaran presented in this paper was designed within the research project Conceptual Design of a High Performance Craft for Passenger Transportation in the Southern Region of Chile. The trimaran was structurally calculated according to the rules of Germanischer Lloyd, Det Norske Veritas and Lloyd’s Register classification societies. A Finite Element Model was created for each set of scantlings and the structural analysis was carried out introducing slamming, splitting and torsional moment loads. Results were analysed and high stress regions were determined and compared to admissible stresses to conclude the suitability of the structural arrangement to safely withstand the design loads. Finally, a structural optimisation was developed using a discreet approach, where, after an iterative process, geometry of structural elements under high stresses was improved, changing shapes and decreasing material thickness, where it was found to be possible. Through this process, the initial structural sizing was optimised, obtaining a reduction between 17% and 25% in terms of material required to build the boat, without exceeding allowable stresses prescribed by classification rules.

Aluminium Optimisation Ship design Structural analysis Trimarans

2015102283

Efficient optimisation framework for robust and reliable structural design considering interval uncertainty. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 63 [9 p, 16 ref, 4 tab, 5 fig] https://www.crcpress.com/product/isbn/9781138027893 Liu, Y., Collette, M.D. English

Marine structural design under uncertainty is a subject that attracts growing interest. This is because inappropriate treatment of uncertainty in early stage design can yield costly consequences such as redesign or even failure of the physical prototype. Early in the design process, many of these uncertainties may not be defined by stochastic distributions as is common in reliability analysis and other risk assessment methods. In this paper, interval uncertainty measures are used to define parameters when adequate information is

lacking. Such uncertainty is assumed to be present in both the geometric configuration of the structure and in the parameters of a reliability-based design constraint. A surrogate-assisted multi-objective optimisation framework is developed to rapidly discover the trade space between structural performance and information availability expressed by various ranges of interval uncertainty. The applicability and efficiency of the method is demonstrated through a simplified mid-ship section structure configuration design with uncertainty in wave loading and bulkhead spacing.

Optimisation Ship design Uncertainty

2015102284

Numeric wake equalizing duct geometry optimisation for a given ship. TransNav, v 9 n 2, June 2015, p 243 [6 p, 9 ref, 6 tab, 13 fig] http://www.transnav.eu/Article_Numeric_Wake_Equalizing_Duct_Martinas,34,579.html Martinas, G., Cupsa, O.S. English

The reduction of fuel cost has always been one of the key strategic business goals for ship owners and operators. In the current climate of high oil prices, the reduction of fuel costs becomes essential; and furthermore a variety of recent legislations require owners and operators to move towards the reduction of emissions from ships. Hence the pressure on designers to achieve both reduced fuel costs and reduced emissions by optimising the hull and propeller has never been higher. In parallel to the performance improvement of new built vessels, there has been great interest in the potential to enhance the performance of existing vessels through retrofit of devices to the hull. In any case for instance the WED device must be customized to fit to the afterbody of the ship in terms of performing its supposed function. The designer is therefore placed in the front of multiple geometric solutions from between he has to make a choice. This paper is intended to help the designers to have a rational choosing approach by involving the numeric optimisation of the geometry of the WED in order to select the best fitted WED to perform the best in order to achieve some predefined parameters. In this paper a given geometry of a WED device is taken and via design optimisation the geometry of the duct was refined so that better results are achieved with a smaller and more compact WED. In doing so, the designer is assisted by numeric

ABSTRACTS 847

optimisation methods to choose from only three final candidates instead of several thousands in order to provide the best fitted WED geometry for a given ship afterbody.

Ducts Hull appendages Optimisation Ship design

2015102285

Application of multi-objective optimisation algorithm in multidisciplinary optimisation of ship design. Shipbuilding of China, v 55 n 3, 2014, pp 53-63 http://oversea.cnki.net/kcms/detail/detail.aspx?filename=ZGZC201403006&DBName=cjfqtotal&dbcode=cjfq Feng, B., Hao, Z., Liu, Z. Chinese

With multi-objective optimisation algorithm based on physical programming an even distribution of Pareto front is able to be obtained, but the optimisation quality need to be improved for complex multi-objective optimisation problem in ship design. In this paper, the applicable effect of physical programming is improved with improving the smoothness of preference function and the adaptability of preference region. Then technology related to the shrink and rotation of search domain is applied to convert the pseudo-preference structure from rectangle to rhombus, while the search of objective space is performed in every direction. On this basis technology in rotating pseudo-preference structure is proposed to further extend search range. Comparing with multi-objective evolutionary algorithm by a numerical example and a conceptual ship design optimisation, the effectiveness of the improved multi-objective optimisation algorithm has been verified.

Algorithms Optimisation Ship design

2015102286

Fatigue strength assessment of propellers by means of weakly coupled CFD and FEM analyses. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4549-3. Volume 7: Ocean Space Utilization; Professor Emeritus J. Randolph Paulling Honouring Symposium on Ocean Technology. Paper No. OMAE2014-24655 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911999 Bertoglio, C., Gaggero, S., Et al English

Propeller design has considerably evolved over the years, continuously imposing new challenges to the designer, from usual high efficiency and avoidance of erosive cavitation up to reduction of radiated noise and pressure pulses for “high added value” ships. New more stringent limits, together with a general requirement for performances optimisation, leads to the need of a continuous review of design procedures which, in some cases, still rely on rather “old-fashioned” approaches. The aim of this paper is to analyse in detail the importance of considering fatigue phenomena in the propeller design, proposing a procedure for the evaluation in time of the stress field acting on a blade during one revolution, which is then considered for fatigue assessment.

Computational fluid dynamics Design Fatigue strength Finite element method Propellers

2015102287

Study on the ship ice resistance estimation using empirical formulas. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4556-1. Volume 10: Polar and Arctic Science and Technology. Paper No. OMAE2014-24182 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912285 Park, K.D., Kim, H.S. English

The ice resistance estimation technique for icebreaking ships has been studied intensively over recent years to meet the needs of arctic vessel design. Before testing in the ice model basin, the estimation

848 ABSTRACTS

of ship ice resistance with high reliability is very important to decide the delivered power necessary for level ice operation. The main idea of this study came from several empirical formulas by B.P. Ionov, E. Enkvist and J.A. Shimanskii, in which ice resistance components such as icebreaking, buoyancy and clearing resistances were represented by the integral equations along the DLWL (Design Load Water Line). However, this study proposes modified methods considering the DLWL shape as well as the hull shape under the DLWL. In the proposed methodology, the DLWL shape for icebreaking resistance and the hull shape under the DLWL for buoyancy and clearing resistances are included in the calculation. Especially when calculating clearing resistance, the flow pattern of ice particles under the DLWL of ship is assumed to be in accordance with the ice flow observed from ice model testing. This paper also deals with application examples for a ship design and its ice model test results at the Aker arctic ice model basin. From the comparison of results from the model test and the estimation, the reliability of this estimation technique is discussed.

Hull form Ice resistance Icebreaking Ship design

2015102288

Innovating the ferry. Marine Technology, July 2015, p 26 [5 p, 3 fig] http://higherlogicdownload.s3.amazonaws.com/SNAME/d7614a0a-1160-449c-8cdb-12d56ad4c697/UploadedImages/McKesson%20feature%2026-30.pdf McKesson, C.B. English

Ferries may seem to most people to be a mature technology, with a few well-known areas for innovation. Generally, these include designs for higher service speeds, lower operating costs, or reduced environmental impact. The purpose of this article however, is to explore a much broader range of opportunities for innovation. The author’s thesis is that innovative vessel designs may be agents for social change, tools for economic development, and opportunities for technological progress.

Ferries Ship design

2015102289

Skimming the surface. Marine Technology, July 2015, p 46 [6 p, 4 fig] http://higherlogicdownload.s3.amazonaws.com/SNAME/d7614a0a-1160-449c-8cdb-12d56ad4c697/UploadedImages/Hockberger%20feature%2046-51.pdf Hockberger, W., Hooker, S. English

This article discusses bringing the wing-in-ground-effect concept to fast ferry design.

Ferries High speed vessels Wing in ground effect craft Ship design

2015102290

Handymax tanker hull and propulsion system optimisation review. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [7 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=04f1a64e-7a28-4b1f-9c39-ae868adb402b Semijalac, G., Buča, M.P., Et al English

This paper deals with analytical, numerical and experimental evaluations performed in order to optimise a Handymax size tanker. The particular parent ship won prestigious global awards and recognition throughout years of service. It was a challenge for Brodotrogir Shipyard designers to gain further improvements. Numerical analyses and experimental testing enabled profound hydrodynamic expertise which led to significant advancement in energy efficiency. The evaluations were done by Brodarski Institute in close cooperation with Brodotrogir Shipyard. Main aim of analytic evaluation was to define hydrodynamic interventions which might be of most interest in practice. Numerical evaluation of hull form proceeded in order to analyse the flow around the hull in more details. Extensive experimental testing followed in towing

ABSTRACTS 849

tank facility. Additional efforts were undertaken to improve propulsion system. Finally, overall gain of total propulsive efficiency of 10% was achieved.

Numerical analysis Model tests Optimisation Propulsive efficiency Tankers

2015102291

Parametric design and multi-objective optimisation of Swath. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [10 p, 13 ref, 7 tab, 26 fig] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=78eae9b9-ef7d-4ae8-bf6f-69ef84ae1f8c Papandreou, C., Papanikolaou, A. English

This paper deals with the development of a parametric design software tool for the fast and robust optimisation of SWATH (Small Waterplane Area Twin Hull) type ships and twin hull ships in general. The prototype SWATH used for validating the results of the developed software is the well-known NTUA-SDL ferry design Aegean Queen. The core of the present paper refers to the development of the parametric hull modelling that enables the automated hull form optimisation of the wetted body. Considering that the design concerns a passenger ship that needs to adapt to different seasonal demands, the optimisation was carried out with regards to two different operational speeds. The first one assumes a high sailing speed for summer operation, while the second one is a relatively low speed for serving at a non-commercial period (winter season). The conducted study demonstrated that the resulting innovative SWATH design has very competitive characteristics regarding powering demand and fuel efficiency, while it disposes the inherent best seakeeping properties especially for operation in short seas, like in the Aegean archipelagos.

Computer-aided ship design Hull form Optimisation SWATH ships

1.3 SHIPBUILDING TECHNOLOGY/CONSTRUCTIONAL TECHNIQUES

2015102292

Bow tie approach in occupational risk assessment in shipbuilding industry. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [9 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=6ac2d702-da26-46d9-b380-a1a664e1446a Fragiadakis, N.G. English

This paper focuses on the description of a proposed Bow Tie methodology, for quantitative risk assessment of occupational risk in the shipbuilding industry. This methodology covers a wide range of risks, related to occupational accidents in a shipyard environment. The aim is to create a reliable methodology, capable of describing the paths from basic danger sources to a possible incident, and from the incident throw safe guards to the possible consequences. In order to accomplish this, fault trees and event trees methodology is proposed matched in a Bow Tie diagram. A distinction of risk is proposed, in order to deal with the diversity and the complexity of a shipyard environment. Finally the author presents an illustrative case study, which focuses on a machine tool – lathe. The advantage of this methodology is that it produced a model, which is capable to impose qualitative conclusions. Furthermore, a full quantification, based on historical accident data, is always possible.

Fault trees Personnel accidents Risk analysis Shipyard safety Shipbuilding

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2.1 POWER SOURCES AND FUELS

2015102293

Electrical power transmission to offshore facilities: a case study. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25704 [9 p] https://www.onepetro.org/conference-paper/OTC-25704-MS Bari, S.J. English

As the world continues its search for energy, many new advanced technologies are being developed. As a result, there is a surge in the amount of electrical power demanded for operations in the oil and gas industry. Satisfying the power demanded by loads in offshore remote locations is an elaborate process. The technical and economic aspects of the alternatives of HVAC and HVDC power transmission have to be scrutinized, before the complex operation of implementing an offshore power supply infrastructure can be executed. After carefully identifying the requirements of a case, the optimum power supply network through appropriate submarine cables can be determined.

Electric power Offshore platforms Power requirements Power supplies

2015102294

Latest trends in power supply for offshore oil and gas industry. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25876 [11 p] https://www.onepetro.org/conference-paper/OTC-25876-MS Santhanamuthu, T., Awda, H., Shabaka, A.E. English

Traditionally, over the decades majority of offshore oil and gas operating companies (OPCOs) have managed their electrical power demand independently using localized open cycle gas turbine generators. With the declining reservoir plateau, adoption of new reservoir development techniques for sustained production, calls for increase in power demand). Alternative means of safe, reliable, environmental friendly and economically viable solutions become inevitable. The objective of this paper is to share experience, key challenges and benefits in developing

a strategic power supply master plan for all offshore OPCO's. The following options of power supply were considered for evaluation: Continue localized gas turbine generation (Business as usual); Renewables (solar, wind, tidal); Formation of power clusters by interlinking facilities and Centralized offshore generation; Power from onshore.

Alternative energy sources Offshore industries Power supplies

2015102295

Application of fuzzy hierarchy process for error detection of auxiliary systems of ship main diesel engines. RINA Transactions - IJME - v 157 part A2, April-June 2015, p 105 http://www.rina.org.uk/ijme.html Demirel, H., Ünlügençoğlu, K., Et al English

This study aims to manage troubleshooting in main engine auxiliary systems which cover cooling, lubricating and cooling oil and fuel systems. The study is also thought to be a good reference for maintenance processes for marine engineering operators. Breakdowns of main engine equipment are examined and a troubleshooting program is developed using a Fuzzy Analytic Hierarchy Process to determine solution methods and causes of such breakdowns. In this paper, a fuzzy Multi Criteria Decision Making methodology is proposed to determine the most effected system of the ship main diesel engine. The results showed that the fuel system was the most effected, followed subsequently by cooling system, governor system, air supply system and oiling system. The results were based upon the opinions of three expert groups who ranked the ship main diesel engine systems alternatives according to twenty-nine criteria selected.

Auxiliary systems Decision theory Diesel engines Fault detection Fuzzy systems

ABSTRACTS 851

2015102296

Technologies for the reduction of nitrogen oxides emissions. TransNav, v 9 n 2, June 2015, p 251 [6 p, 8 ref, 9 fig] http://www.transnav.eu/Article_Technologies_for_the_Reduction_Arsenie,34,580.html Arsenie, P., Martinas, G., Et al English

When it comes to gas turbines, their main problem concerning pollutant emissions is represented by nitric oxides. Among other emissions, sulphur oxides being much reduced due to the use of liquid distilled and gas fuels with a low content of sulphur. Using water or steam injection became the favourite method during the 1980s and especially the 1990s since "dry" methods and catalytic reduction were both at the beginning of the development phase. Catalytic convertors have been used since the 1980s and they are still used although the costs of renewing the catalyst are very high. In the last twenty years a gradual decrease has been registered on the limits of nitric oxides from 75 ppm to 25 ppm, and now the target is oriented towards the 9 ppm level. The evolution of burning technologies of combustion makes it possible to control the level of production of nitric oxides even from the source without being necessary to use "humid" methods. This, of course, opened the market for gas turbines because they can function even in areas with limited quality water reserves, such as maritime platforms and in the desert. This paper shows that, although water injection is still used, "dry" control technologies of burning became favourite methods for the majority of users on the industrial power generators market. The great dependency between the creation of nitric oxides and the temperature reveals the effect of direct water or steam injection on reducing nitric oxides. Recent research showed that a reduction up to 85% of nitric oxides may be obtained by using the water or steam injection all together with the improvement of aerodynamic characteristics of the burning room.

Emissions Gas turbines Reduction

2015102297

Electric future. Marine Technology, July 2015, p 7 [4 p, 2 fig] http://higherlogicdownload.s3.amazonaws.com/SNAME/d7614a0a-1160-449c-8cdb-12d56ad4c697/UploadedImages/MTNote%20Dauncey%207-10.pdf Dauncey, G. English

This article discusses how renewable energy technologies are impacting the ferry sector.

Ferries Power supplies

2015102298

New propulsion concept: Powerhouse tug & barge system. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [11 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=e44c4e2f-f08e-48ca-8937-a7a9b3ad6042 Majumder, M.R. English

The multi-function Powerhouse Tug & Barge (PTB) system is a novel design that utilizes electric propulsion in the barge and a tugboat with a set of generators as a power pack. This concept has two basic differences with traditional ATB (Articulated Tug & Barge) system. First, though the barge will have electrical propulsion gear onboard, the propulsion power will come from the tug, acting as a powerhouse. Secondly, the Powerhouse Tug will be connected at the bow of the barge rather than at the stern and will be pushed by the barge when propelling. The control will be onboard the Powerhouse Tug. The greatest advantage of this concept is that the tug can be designed to serve as a traditional tow boat, pusher in ATB configuration, as well as a Powerhouse Tug in PTB configuration, serving all kinds of barges and vessels while the barge can be designed for highest propulsive efficiency with ship shape stern.

Electric propulsion Tug barge systems

852 ABSTRACTS

2015102299

First-law and second-law waste heat recovery analysis of a four-stroke marine diesel engine equipped with a regenerative organic Rankine cycle system. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [11 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=e8becbca-3d72-4372-8e96-70b0510052e8 Yfantis, E., Katsanis, I.S., Et al English

In this study a thermodynamic model was developed and used to assess the first-law and the second-law performance characteristics of a four-stroke marine diesel engine equipped with a regenerative organic Rankine cycle (RORC) bottoming system. Initially, the first and the second law of thermodynamics were utilized to comparatively evaluate the performance characteristics of a diesel-RORC and a diesel-ORC bottoming systems using the same dry organic fluid (i.e. R245ca) and under the same cycle high pressure (i.e. 8 bar). Afterwards, the effect of bottoming cycle high pressure on the marine diesel-RORC system first and second law performance parameters was investigated considering the same dry organic medium (i.e. R245ca). Finally, the theoretical analysis was concluded by examining the effect of dry organic fluid on marine diesel- RORC energetic and energetic performance characteristics. This investigation was facilitated considering four different dry organic fluids namely R123, isobutane, R245fa and R245ca. The assessment of the theoretical results revealed that the highest improvement of the overall energy and energy efficiency of the marine diesel-RORC system is attained using a subcritical bottoming cycle with isobutane as working medium and cycle high pressure close to the critical one.

Diesel engines Four stroke engines Heat recovery Rankine cycle

2015102300

The case of LNG as fuel for merchant vessels in the special emission control areas. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [10 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=c352c371-dd20-4ed4-b350-aea9e1431a4d Corres, A.J., Frangos, A., Papachristou, Y. English

The issues connected to the introduction of the SECAs by January 1st 2015 are numerous and interconnected constituting a mesh of problems through which ship owners and charterers have to pass. Decisions have to be made amid uncertainty and are bound to influence a much wider number of players than the two aforementioned ones. The European Union, itself confused about incentives and subsidies, is unable to provide assistance to its affected member states which will be left to their own devices. The same applies to ship owners who see the huge amounts of money available under the various schemes go to infra-structure projects rather than the cost of retrofits. There is no doubt there is going to be an impact on the terms of trade and most writers on this subject agree there will be higher freight rate levels in short sea shipping and a significant degree of backshift of cargoes from the sea to the land modes. This summary paper attempts to depict the larger picture in a concise way and suggests that the problem has been approached from the wrong angle ab originem.

Emissions Liquefied natural gas Scrubbers

2015102301

Electrical characteristics of cold ironing energy supply for berthed ships. Transportation Research Part D: Transport and Environment, v 39 August 2015, pp 31-43 http://www.sciencedirect.com/science/article/pii/S1361920915000796 Sciberras, E.A., Zahawi, B., Atkinson, D.J. English

The reduction of emissions in harbours is of particular importance due to the proximity to human habitation. Vessels normally run onboard generators, typically using diesel fuel, to provide the service loads while berthed. New and upcoming regulations aim to decrease emissions from shipping, and coupled

ABSTRACTS 853

with increased environmental consciousness of ship owners and harbour operators, shore supply is becoming a more popular and feasible option. Cold ironing provides an alternative locally emission-free solution by having berthed ships plug in to the shore electrical network, such that the onboard electrical energy demand is supplied from land. Electrically, a number of different shore network topologies are possible, providing different infrastructural options of supplying power to multiple berths. This paper examines the electrical characteristics of one such installation and the impact on the shoreside electrical network for an existing port using actual visiting ship power profiles. The paper examines how the cold ironing system influences important electrical network characteristics such as bus voltages and power quality, as well as the potential impact on the rest of the utility distribution system.

Berthed vessels Electric power Frequency converters Onshore Power supplies

2.2 EQUIPMENT AND INSTALLATIONS

2015102302

Overcoming inertia towards new inert gas systems. The Naval Architect, June 2015, p 36 [2 p, 2 ref, 1 tab, 9 fig] http://www.rina.org.uk/tna.html Lauritzen, F. English

Twin bed dry inert gas generators have been the industry standard for years; this article outlines how advances in drying technology mean that shipowners and shipyards have a genuine alternative.

Inert gas generators Inert gas systems

2015102303

Anchor windlasses: a design proposal to standardise regulations. RINA Transactions - IJME - v 157 part A2, April-June 2015, p 95 http://www.rina.org.uk/ijme.html Carral Couce, J.C., Carral Couse, L., Et al English

Shipbuilding is an increasingly competitive field. As the key players in this activity, shipyard managers

have to make their counterparts in related industries aware of two conflicting needs. On the one hand, they must produce high quality components that are technologically advanced. On the other, they need equipment that lets them build vessels at a reasonable price. With this second aim in mind, it would be useful to standardise both design and manufacturing processes. At the same time, ship owners always impose regulations. The manufacturers of deck equipment must therefore adapt their product designs to comply with these regulations, some of which have aspects in common. However, guidelines also differ on many points. This makes it difficult to reach desirable levels of standardisation in equipment design. The situation can be summed up in a phrase: for each vessel, a specific design. This article first provides a comparative overview of current legislation. A proposal for anchor windlass design is then presented in an attempt to make the various regulations more cohesive. The objective here is to reach an acceptable degree of standardisation and, consequently, lower costs by applying economies of scale.

Anchor windlasses

2015102304

Solution to reduce air environmental pollution from ships. TransNav, v 9 n 2, June 2015, p 257 [5 p, 5 ref, 1 tab, 7 fig] http://www.transnav.eu/Journal_Vol._9_No._2-June_2015,34.html Pham, H.T., Nguyen, T.M. English

Exhaust gas emissions from ships are increasingly polluting the air environment seriously. Therefore, the MARPOL 73/78 Annex VI is applied for all ships from 2017, Annex VI provided that the concentrations of NOx, SOx and CO contained in ship’s exhaust gases must be less than 6.4 g/kWh, 0.6 g/kWh, and 5.5g/kWh respectively. Today, there are many solutions to reduce pollution emissions from exhaust gas of ships, such as improving combustion, using oil emulsion, using biofuel, however, these solutions also have a handful of disadvantages such as being unable to thoroughly resolve problems, high cost, and very difficult to improve the quality of ship exhaust gas emissions for old ships. Exhaust gas treatment method uses a centralized treatment system where exhaust gas from the thermal engines is taken in a centralized treatment system before discharging into the air. After centralized treatment system, in comparison with raw exhaust gas, soot can be

854 ABSTRACTS

reduced by 98%, NOx can be reduced by 75%, SOx can be reduced by 80%. This method of treatment is not only low cost and good quality but also allows marine heat‐engines to still use traditional fuels as well as no need to improve its structure.

Air pollution Emissions Exhaust gases Reduction Treatment

2015102305

Ship efficiency improvement by means of CLT propellers technical and financial. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [8 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=e32e4b3e-8b47-42b8-924a-ba86d57096d7 González-Adalid, J., Pérez Sobrino, G., Et al English

Energy saving is a primary objective in the design of marine propellers, in addition to high oil prices and stricter regulations driving a need for energy efficiency. CLT propellers, thanks to their higher efficiency compared to any other propeller type, are a primary tool for reducing fuel consumption. This paper presents the design and benefits of CLT propellers and relevant testing results. Given the ongoing difficult market and lack of liquidity, it is often difficult for shipowners to make this investment. Niche solutions are available by Efficient Ship Finance at no upfront cost to shipowners. In particular the shipowner is provided with the full capital for the upgrading, which is repaid by a share of the fuel savings achieved, the details of which are outlined in this paper. This paper presents three sample upgrades, both for newbuilding and retrofit scenarios, for a 42.000dwt, a 63.000dwt, and an 180.000dwt bulk carrier.

Energy conservation Propulsive efficiency Retrofitting Tip loaded propellers

2015102306

An overview of hydrodynamic energy efficiency improvement measures. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [11 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=27effc34-55cb-4dd2-a365-78932a7904be Gougoulidis, G., Vasileiadis, N. English

The energy control and efficiency of ships has been and will continue to be a matter of increasing importance in the years to come. Due to the large number of energy efficiency measures available, the current paper focuses on the measures which improve the hydrodynamic efficiency of ships. The systems that are examined are divided into two groups: hull systems (e.g. bow bulbs, stern flaps, and appendages) and energy saving devices. Specifically, the latter are defined mainly as systems that are installed in the vicinity of the propeller-rudder zone. In this context, alternative propeller configurations are also examined. State-of-the-art systems from each category are presented along with working principles, as well as the savings quoted by the manufacturers.

Efficiency Energy conservation Hull appendages

2.3 MAINTENANCE, REPAIR AND CONVERSION

2015102307

A new recommended practice for inspection planning of fatigue cracks in offshore structures based on probabilistic methods. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4545-5. Volume 5: Materials Technology; Petroleum Technology. Paper No. OMAE2014-23188 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911720 Lotsberg, I., Sigurdsson, G. English

During the last 30 years a methodology for planning in-service inspection of fatigue cracks based on probabilistic methods has been developed. Due to the nature of the fatigue phenomena it is well known that

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minor changes in basic assumptions can have significant influence on the predicted crack growth lives. Calculated fatigue lives are sensitive to input parameters using standard design analysis procedures. Calculated probabilities of fatigue failure using probabilistic methods are even more sensitive to the analysis methodology and to input parameters to the analyses. Fracture mechanics analysis is required for prediction of crack sizes during service life in order to account for probability of detection after an inspection event. Analysis based on fracture mechanics needs to be calibrated to that of fatigue test data or S-N data. Thus, use of these methods for planning inspection requires considerable education and engineering skill. Therefore the industry has asked for guidelines that can be used to derive reliable inspection results using these methods. DNV has during the last years performed a joint industry project on use of probabilistic methods for planning in-service inspection for fatigue cracks in offshore structures. The recommendations from this project are now being included in a DNV Recommended Practice. The main background for this document is presented in this paper.

Fatigue cracks Inspection Offshore structures Planning Probabilistic methods

2015102308

A statistical study of dry dockings, hull cleanings and propeller polishes. SNAME Western European Section. Paper presented 14th May 2015 [7 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=58af8b47-f3b7-4984-9afb-a71c68410105 Dirksen, T., Gundermann, D. English

A statistical study of dry dockings, hull cleanings, and propeller polishes has been carried out. The study shows that dry dockings in average reduce the level of added resistance to 15.4%; however, the individual dry docking result depends on the level of added resistance before the dry docking, and presumably on the dry docking treatment. Furthermore, there is a weak dependence on the ship age. Similar linear relationships between the level of added resistance before an event and after have been found for hull

cleanings, propeller polishes, and combined hull and propeller cleanings. From these relations, it has been shown that combined hull and propeller cleanings gives a higher saving than both hull cleanings and propeller polishes as expected. Hull cleanings and propeller polishes give approximately the same saving statistically. Finally, it has been shown that the development rate in average increases after hull cleanings and propeller polishes, but is approximately unaltered for dry dockings.

Drydocking Hull cleaning Polishing Propeller cleaning Statistical analysis

2015102309

Risk and reliability analysis tool development for ship machinery maintenance. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [10 p, 24 ref, 2 tab, 4 fig] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=78eae9b9-ef7d-4ae8-bf6f-69ef84ae1f8c Dikis, K., Lazakis, I., Et al English

Concerning the successful business competence, strategic planning should be enhanced considering assets availability by involving maintenance and reliability operational aspects. The INCASS (Inspection Capabilities for Enhanced Ship Safety) FP7 EU funded research project aims to tackle the issue of ship inspection, identification of high-risk ships, providing access to information related to ship surveys and incorporate enhanced and harmonized cooperation of maritime stakeholders in order to avoid ship accidents, promote maritime safety and protect the environment. The current research consists of machinery and equipment specifications and stakeholders’ data requirements. Focusing on the methodology perspective, a Machinery Risk Analysis model is introduced. All progress and methodology development takes place in Java programming language. Overall, the outcomes of this study demonstrate the reliability performance of marine machinery components. Future development include dynamic failure rate variation through time,

856 ABSTRACTS

probabilistic model’s sensitivity analysis and components’ and systems’ interdependencies in a user friendly Graphical User Interface design.

Condition monitoring Machinery maintenance Probability Reliability Risk analysis

2.4 CARGOES AND CARGO HANDLING

2015102310

Development and Qualification of a Tandem FLNG Loading Terminal for Conventional LNG Carriers. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25980 [24 p] https://www.onepetro.org/conference-paper/OTC-25980-MS Hellesmark, S.B., Andersen, P.G., Thorsen, T.B. English

The first floating LNG (FLNG) projects are now under construction and more than 25 new FLNG projects are currently being planned worldwide. One of the most critical systems for the overall safe and reliable operation of an FLNG is the LNG offloading system. The preferred option for most of the operators is to perform offloading in a tandem configuration. The challenge with such a solution is that it will normally require expensive dedicated LNG ships with dynamic positioning and LNG Bow Loading Systems. This paper describes the development and qualification of a tandem LNG offloading solution that solves this industry challenge. A dynamically positioned LNG loading terminal has been developed to enable a safe and reliable LNG transfer operation from a FLNG to any conventional LNG Carrier without any modification to the LNG ships.

Floating docks LNG handling LNG terminals Tandem arrangement

2015102311

Terminal and transportation risk assessment for LNG export in North America. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26020 [14 p] https://www.onepetro.org/conference-paper/OTC-26020-MS Hamedifar, H., Spitzenberger, C., Et al English

This paper gives an overview of method development in quantitative risk analysis for marine terminals and transportation that have been applied to several of the planned LNG and LPG transportation projects in North America. The growth in natural gas production in North America has renewed interest in exporting natural gas, mostly in the form of LNG or LPG. However, this growth comes with transportation challenges as suppliers, and operators move products and equipment, to and from an expanding number of sites (many of them in remote locations). Maintenance of safety and security practices is increasingly important as operations become geographically dispersed and more diverse. Analyses of reliability and risk are potentially most valuable during the early stages of marine terminal projects in guiding the decision on siting, design, and operative risk controls to reduce the risk as low as reasonably practical in final development. An important development in quantitative risk analysis for marine transport is the ability to utilize “big data” resources like Automatic Identification System (AIS) tracking. Utilizing AIS data provides the best available picture of existing traffic in a waterway. Quantitative risk analysis applies historical data as the basis for estimating risk of future accidents. This paper gives examples of how to combine historical data and advanced failure mode modeling to better estimate risk for loss of containment from LNG and LPG carriers. Quantification of accidental release frequencies and consequences of a release are demonstrated in this paper. The risk level for gas terminals and transportation area expressed in terms of individual risk at the terminal and along the transportation route. Newly developed methods make it possible to show the risk along the sailing route, accounting for the variation in traffic and

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environmental parameters along the route. Understanding of the key drivers of risk is important for the decision-makers to establish adequate risk controls for new energy export projects.

LNG terminals LNG transportation Risk analysis

2015102312

Risk assessment for oil transhipment applying PFMEA & TOPSIS. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [9 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=5f1bfcf3-db32-4a8c-9aac-6cf190d327b9 Stavrou, D.I., Ventikos, N.P. English

Ship-to-ship (STS) transfers have become common practice, nevertheless, the catastrophic consequences of a potential accident addresses the crucial importance of a detailed risk assessment. To this end, the Process Failure Mode and Effects Analysis (PFMEA) were properly modified in this paper for the transhipment of cargo. Despite the advantages, PFMEA has serious draw-backs, which make the methodology weak and ineffective. An alternative way to deal with the weaknesses is to apply the fuzzy Technique of Order Preference by Similarity to the Ideal Solution (TOPSIS). The aim of this paper is to assess and evaluate different hazard scenarios in an STS transfer operation, implementing the PFMEA in combination with the fuzzy TOPSIS. Thus, a team of experts with relevant experience of STS transfer operations evaluated hazard scenarios derived from the study of relative guidelines and recommendations. The results are compared to those of the traditional Risk Priority Number (RPN) calculations. The paper concludes with interesting insights.

Oil transfer Risk analysis

2015102313

Decision support tool for simulation and optimisation of cargo handling procedures of tankers. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=78eae9b9-ef7d-4ae8-bf6f-69ef84ae1f8c Plessas, T., Chroni, D., Et al English

In recent years the shipping industry has been challenged by the adverse conditions of the world economy, the steep increase of fuel (bunker) prices and new inter-national environmental regulations (Emission Control Areas, water ballast treatment, etc.), which have all drastically increased the operational cost and reduced the profit margins for ship owners and operators. To address this situation, the maritime industry is putting increased efforts in the implementation of various energy/cost saving practices, like slow steaming, optimisation of routing, installation of propulsive efficiency enhancing devices etc. In this context, this research study focuses on the modelling and optimisation of the cargo pumping systems of tankers for least energy/fuel consumption. In this context, a new software tool has been developed, consolidating the operational constraints of the cargo discharging procedure in terms of ship stability/trim and strength, while optimising the overall energy efficiency of the vessel during a discharging procedure.

Cargo handling Cargo pumps Decision support systems Optimisation Tankers

2.5 PORTS AND WATERWAYS

2015102314

Conceptual design of an offshore LNG bunkering terminal: a case study of Busan Port. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 226-237 http://link.springer.com/article/10.1007/s00773-014-0266-1 Yun, S, Ryu, J., Et al English

This study proposes the conceptual design of an

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offshore liquefied natural gas (LNG) bunkering terminal that would play a critical role in the LNG supply chain for LNG-fueled ship propulsion. The principal functions of the LNG bunkering terminal include importing LNG from LNG carriers, storing it temporarily, and exporting the stored LNG to LNG bunkering shuttles or LNG-fueled ships. One of the critical issues facing cargo operation from a safety point of view is the treatment of boil-off gas (BOG) generated from several sources in the storage systems of the bunkering terminal. Several methods of handling BOG seem feasible. The employment of a pressure vessel with a re-liquefaction system is considered the most effective and safe alternative. As a case study, a conceptual design of Busan Port is carried out by analysing the statistics of visiting ships, estimating the required LNG consumption, determining the hull structure, and anticipating the design cases. The results obtained include the number of target LNG-fueled ships and LNG bunkering shuttles, LNG demand, capacity, and type of hull structure for the bunkering terminal. To estimate the process specifications and equipment features of the topside system, the BOG generated from several sources is calculated.

Design LNG terminals

2015102315

Waste reception facilities in cruise ports: the case of the Med. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=78eae9b9-ef7d-4ae8-bf6f-69ef84ae1f8c Pallis, A.A., Papachristou, A.A. English

With cruise activities in the Mediterranean and its adjoining seas increasing, the cruise world takes initiatives to handle the produced externalities, including the wastes produced on cruise ships. In recent times, cruise lines and ports have put a lot of efforts into reducing, selecting and managing generated wastes implementing the requirements of the international regulatory framework (MARPOL 73/78) as well as those imposed by the European legislation. The authors surveyed the extent that the current practices of cruise ports in the Mediterranean region have achieved a satisfactory level of compliance. It does so via a survey that maps the existing conditions and port based practices in

approximately 50 cruise ports in the region. The study concludes on the kind of facilities, technologies and services that are present at Mediterranean cruise ports. Beyond the empirical knowledge the study provides practical implications on what further can be done so as to secure a sustainable cruise future.

Passenger terminals Port facilities Waste disposal

2.6 COASTAL/OFFSHORE ENGINEERING AND MARINE RENEWABLE ENERGY

2015102316

Experimental study of a hybrid mooring system. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 213-225 http://link.springer.com/article/10.1007/s00773-014-0260-7 Ji, C., Yuan, Z. English

Mooring systems are essential to the floating structures including offshore platforms, wave energy converters and floating breakwaters. As floating structures propagate towards deeper waters, the design of the mooring systems needs to be revamped. In the present study, a new hybrid mooring system has been proposed. A series of weights and buoys are arranged to the different segments of each mooring line in order to improve the motion performance of the platform and eliminate the vertical forces at the lower end of the mooring lines. A series of experiments have been carried out in a wave basin for a semi-submersible platform moored by the mooring lines with or without the weights and buoys. The mooring lines’ tension and 6-DOF motions of the platform were measured. Discussions have been made on non-linear motion responses of the semi-submersible and non-linear mooring line tension responses for various mooring conditions.

Mooring lines Mooring systems Platform motions

ABSTRACTS 859

2015102317

Challenges in wave force modelling for mooring design in high seas. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25944 [17 p] https://www.onepetro.org/conference-paper/OTC-25944-MS Stansberg, C.T., Kaasen, K.E., Et al English

Line breakage events have been experienced on moored structures during recent years. These often occur in heavy weather and overload is one of the reasons. This paper identifies possible physical phenomena that may lead to wave forces higher than predicted by state-of-the-art hydrodynamic tools and procedures, and thereby higher mooring line loads, in high and steep waves. In particular, a need to re-explore wave-group induced slowly varying, low-frequency (LF) drift forces has been identified. Both mobile offshore units and permanently moored floaters are considered, semisubmersibles and FPSOs. Empirical corrections are sometimes applied in design of mooring lines, while not in general, and there is no established common industry practice on such corrections. More advanced tools and knowledge do exist in research communities, while they still need further development for robust engineering use. A brief overview is given of state-of-the-art methods and tools in modelling of the hydrodynamic forces on large-volume floaters, with particular focus on slowly varying wave forces. Full scale experiences from real sea events and from a variety of earlier case studies including model tests are reviewed. It is found that several items may be critical in the proper prediction of LF wave forces in high seas and combined current and should be investigated further, in particular: wave-current interaction; viscous wave drift forces and large and nonlinear wave-frequency vessel motions. Based upon these preliminary investigations, the paper gives recommendations for actions and further developments for improved predictions in industry practice.

Heavy weather Mooring lines Wave forces

2015102318

Creating sustainable offshore developments in the ultra-deep water. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25873 [11 p] https://www.onepetro.org/conference-paper/OTC-25873-MS Rijtema, S., Haas, R. de English

The continuous drive to increase oil and gas production requires fields to be developed under challenging circumstances such as deeper water, harsh operating and environmental conditions and remote areas all while adhering to strict HSE requirements. At the same time, investment decisions for an increasing number of projects have been postponed because the increasing costs have resulted in reduced shareholders return. In order to overcome the technical challenges within the changing environment, funding needs to be created by improving the cost effectiveness of the adopted solutions. This can be achieved by optimising and standardizing the current concepts and by using the research in and outside our industry, to benefit from innovations, which can reduce risks and save costs. At the same time, lessons captured in the past decade need to be imbedded within the organizations which requires retaining, training and guidance of the engineers and building on the technical relations within the supply chain. The other side of the deep-water challenge is the current technical limitations, which need to be overcome. Equipment that is currently available and their applications need to be revised to deliver the step change to the ultra-deep water. This paper focuses on the areas, which combine extensive installation experience with more recently gained SURF EPCI insights and the ongoing technology developments with the intent to create practical solutions for the industry. It describes how the authors intend to use real time simulators to identify and manage risks during the offshore construction. Also, topics such as lowering capabilities for the ultra-deep water, flexibility in field developments, smart design which incorporates vessel capabilities, coating and welding developments for the high pressure, high temperature fields and the implications of remote areas are addressed.

Deepwater Offshore drilling Offshore industries

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2015102319

The cylindrical hull concept for FLNG application. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25703 [29 p] https://www.onepetro.org/conference-paper/OTC-25703-MS Odeskaug, L. English

Cylindrical hulls are currently in use for FPSOs, drilling rigs and accommodation units. The objective of this paper is to describe how the cylindrical hull concept now has been developed to also be applicable to FLNG. To provide a more stable and economical hull configuration, the use of a cylindrical hull as a platform for the gas pre-treatment and liquefaction plant has been studied and generically developed using advanced analytical design tools. The behavior of the cylindrical hull has been model tested and a significant amount of data is also available from the cylindrical FPSOs in operation. The cylindrical hull has significantly less pitch and roll motions than a conventional ship shaped hull, and eliminates the need for a turret and swivel. Hence it provides a stable platform for the process plant and has the potential to enhance project development and operations. The cylindrical FLNG concept is a further development of the proven cylindrical FPSO design. The hull meets the requirements of the International Gas Code and has been developed to accommodate both SPB and Membrane cargo containment systems. The hull has double sides and bottom, and the ballast tanks are in the double sides. There are three decks, main deck, intermediate deck and the process deck. Utility and safety equipment, such as lifeboats, water-makers, heat exchangers, etc. are located on the main and intermediate decks. The gas pre-treatment and liquefaction plant along with power generation and living quarters are on the process deck. For offloading a novel development using an L-shaped DP assist vessel is proposed. This allows for loading of standard LNG Carriers at a safe distance from the FLNG in sea states of Hs 4m. The L-shaped unit is a specially designed vessel that attaches to the LNG carrier and guides it during approach and departure and keeps the LNG carrier at a safe distance of 150 – 200 m from the FLNG during

the offloading operation. The cylindrical FLNG in combination with the novel offloading technology for offshore LNG transfer offers a safe, reliable and cost efficient solution to the emerging FLNG market.

Cylindrical bodies Floating production systems Hull form Liquefied natural gas

2015102320

Deep offshore gas fields: a new challenge for the industry. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25802 [13 p] https://www.onepetro.org/conference-paper/OTC-25802-MS Gyllenhammar, E., Boireau, C., Et al English

A large number of gas fields have recently been discovered offshore in depths of up to 3000 m, far away from the nearest coast and in countries with little or no oil and gas infrastructure. In addition to the field development strategies including large surface facilities for processing and export to shore, or floating LNG plants, the industry may in the future be seeing more subsea-to-shore developments for these fields. Total and Aker Solutions have completed a study for a challenging notional gas field development located at 2500m water depth, 300 km from shore, that is to be developed using only subsea technology. The vision is a fully autonomous subsea production system with tie-back to shore. This paper describes the flow assurance challenges with long-distance subsea tie-backs to shore, from deep offshore fields, and the work done to identify the wide range of subsea processing schemes that may improve the gas transport. Two of these schemes were selected and studied in detail: one consisting of pushing the envelope of multiphase transport to shore with the aid of a subsea compression system, and the other of developing a system for subsea gas dehydration to avoid the use of Mono Ethylene Glycol (MEG) for hydrate inhibition. The main challenges of using these technologies are presented and discussed.

Deepwater Gas fields

ABSTRACTS 861

2015102321

Disconnectable mooring systems for Arctic conditions. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25910 [21 p] https://www.onepetro.org/conference-paper/OTC-25910-MS Bauduin, C., Boulard, R., Et al English

This paper reviews the issues associated with mooring a ship shaped Floating Production Unit (FPU) in arctic conditions, and presents the development of a novel disconnection and reconnection system for such conditions. The mooring systems of FPUs operating in arctic conditions must be disconnectable to allow the FPU to leave the station to avoid collision with icebergs, or to avoid overloading the mooring legs due to sea ice acting on the FPU hull. In the case of sea ice, the FPU may be required to disconnect under much higher loads than the non-arctic disconnectable systems in operation today. A recent study for the design of an arctic mooring system identified a number of key developments that are required before such systems could be deployed. The disconnection system is a safety critical element, and requires high reliability and redundancy to ensure the FPU can always rapidly disconnect from its mooring when required. In addition, the large number of risers that may be installed for these large field developments, combined with the significant suspended weight resulting from the high capacity mooring system, leads to large buoyancy requirement for the buoy which must support the risers and mooring system when disconnected from the vessel. As a consequence the analysis of the reconnection process must account for the coupled behaviour of the large buoy body, the mooring system, and the risers and umbilicals. Such analysis has shown that using conventional disconnectable turret technology, the large buoy size coupled with the requirement to reconnect in heavy sea states, can readily generate snatch loads that would break the pull-in winch wire. In response to the above, this paper presents two significant advances in disconnectable mooring technology. The first is the development of a new locking system to connect the buoy to the turret, which has been

qualified at full scale. The second concerns the design of a new pull-in arrangement that eliminates the risk of snatch loads even in sea states in excess of 3m Hs. The system robustness has been demonstrated through model testing.

Arctic environment Floating production systems Mooring systems

2015102322

Enhancing air gap design and assessment in deepwater floating system performance. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25986 [11 p] https://www.onepetro.org/conference-paper/OTC-25986-MS Wu, W., Zeng, J. English

This paper discusses how to enhance air gap design and assessment for the deepwater floating systems. The authors first establish an analytical method to predict air gap considering global upwelling due to wave diffraction, as well as random wave effects. Then the authors apply the analytical method to simulate the air gap of typical deepwater floating systems through uncoupled analysis combining frequency domain and time domain global motion analysis. For comparison, a coupled analysis with hull structure, mooring and riser system is also carried out. The authors then look into model test verification and correlation analysis of air gap prediction, especially how to deal with random motion effects on deriving the extreme values of air gap. Furthermore, the authors illustrate how to improve deepwater floating system performance and cost-effectiveness by utilizing a practical and reliable air gap design approach. The air gap simulation results derived from the proposed analytical procedure correlate well with the wave basin model test results. This analytical procedure has also been applied to deepwater floating system design for field development projects, which can be considered as a practical and reliable air gap design solution for optimising global configuration to improve deepwater floating system performance and cost effectiveness.

Air Deepwater Gaps Floating structures

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2015102323

Experimental investigation of extreme waves - comparison with analytical models and CFD. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25973 [24 p] https://www.onepetro.org/conference-paper/OTC-25973-MS Bahuguni, A., Wu, Y., Et al English

The study of extreme sea states and predictions of associated wave kinematics form the basis for the design and re-assessment of offshore structures. This paper compares analytical and numerical models with scaled wave flume experiments that were carried out at the University of Aberdeen, UK, to measure surface elevation profiles and the velocity beneath extreme crests. Focused wave groups representing the extreme events were generated at a given point in space and time. The input amplitude spectra for the flap-type wave maker were derived using Tromans’ NewWave theory which corresponds to the autocorrelation of the surface spectrum. The sea states in the experiments were chosen to represent extreme waves in the North Sea and Australian waters. The effects of nonlinear wave-wave interactions, which shift the actual focus point and focus time from the linear position, are analysed and discussed. The results from second order NewWave theory and higher order stream function waves are compared with the experimental results to evaluate the validity range of these analytical models. CFD simulations are also conducted and the results are compared with the experimental values.

Computational fluid dynamics Experimentation Extreme waves

2015102324

Extending anchor handling vessel capabilities and the technical innovations that make it possible. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26044 [14 p] https://www.onepetro.org/conference-paper/OTC-26044-MS Miller, J.D., O’Driscoll, MA., Farrow, M. English

As more structures are installed in offshore deepwater locations, the demands on the fleet of vessels that support the work increase. Deeper installation depths require the employment of emerging technologies and

novel installation practices to safely accomplish installation and commissioning of the station keeping system. Deepwater operations can be costly and operators often enter extended contracts with vessel owners to support a variety of offshore operations as a cost reduction measure. In the autumn of 2014, the Delta House floating production system (FPS) was connected to its pre-set taut-leg mooring system in approximately 4,500 feet of water. Mooring installation costs were reduced by utilizing an anchor-handling vessel (AHV) already on long-term contract with the Operator's drilling department. The Delta House hull and mooring designs were created by EXMAR Offshore, and the mooring components were specified and ordered knowing that the components exceeded the handling capacity of the selected installation vessel. This created unique challenges as the normal handling practices and equipment could not be employed. This paper summarizes the challenges and solutions found during the installation of the Delta House FPS for LLOG Exploration. It highlights innovations that extended the installation vessel's capacity and compares the size of the Delta House mooring components with those installed for LLOG's previous OTPI-Ex hull (Who Dat) in 2011. It describes enabling technologies that made installation possible with the specified asset.

Anchor handling vessels Floating production systems Installing Mooring systems

2015102325

FLNG: applying advanced technology to bring more natural gas to market. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25907 [8 p] https://www.onepetro.org/conference-paper/OTC-25907-MS Boekhorst, A., Steenson, B., Velde, H. van der English

The development of FLNG is complex. Shell has been working on FLNG technology since the mid-1990s drawing on more than five decades of expertise in LNG technology, LNG shipping and operating offshore facilities. Shell's approach to FLNG is to design for safe, high availability and reliable production using proven technologies. The constraints of space and seaworthiness however, required the designers to assemble these technologies in novel configurations. Examples include the internal turret -suitable for tie-back of complex subsea

ABSTRACTS 863

systems and harsh meteocean conditions, a double wall substructure hosting the product storage tanks, processing equipment that has been modified to allow it to operate efficiently under marine conditions and specially designed cryogenic loading arms able to operate in a dynamic offshore environment. The safety of the FLNG facility has been foremost during its design. The topsides layout has been developed using Quantative Risk Assessments and rigorous process safety standards. The layout also includes 20 meter safety gaps across the full width of the FLNG barge between the main processing modules with escape routes along both sides of the facility, as well as through the central alley. Shell is applying standardisation as a philosophy for its FLNG design, so that developments can become faster and more cost effective. Based on this philosophy, the authors have also developed a FLNG solution designed for leaner gas fields that has many similarities when compared to the standard FLNG design. The so called ‘FLNG Lean' can be applied on fields with lower liquids yields and, by optimizing liquid handling and storage facilities, FLNG Lean is able to deliver higher LNG production capacities.

Floating production systems Liquefied natural gas

2015102326

Floater concept selection for ultradeep waters in Brazil. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25937 [11 p] https://www.onepetro.org/conference-paper/OTC-25937-MS Toro, L.F.B., Saraiva, T.C., Et al English

Uncertainties on design basis during early design stages of offshore fields are a known challenge to deal with when selecting feasible development options. Ultra-deep water discoveries have hampered these choices. The scope of this paper is to describe the methodology applied for the identification of most suitable floater(s) to operate in an ultra-deep waters block located in the Campos Basin south-east of Rio de Janeiro in Brazil. The block of study is located in a remote area far from shore within water depths nearly to 3000 m. FPSO and semisubmersible floaters are identified as the most preferable floaters. The paper

will show the combination of most important design players and decision trees for reaching flexible solutions feasible for several production scenarios at an early project stage. Technical players such as Brazilian environmental conditions, variable risers and topsides loads, variable storage capacities, and floater motion restrictions have been combined with commercial and risk players, such as ultra-deep waters technology maturity, local content, market requirements, shipyards capacities and previous experience in the country with solutions adopted in similar fields, locations or depths. As a result, the study shows a number of floater options integrating one or two hulls feasible to develop on further design stages.

Deepwater Floating production systems FPSOs Semisubmersibles

2015102327

Lucius spar: design to delivery. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26024 [16 p] https://www.onepetro.org/conference-paper/OTC-26024-MS Tule, J. English

This paper provides an overview of the design and installation of Anadarko’s Lucius Truss Spar. The design and engineering of the spar and mooring systems were performed using the most current environmental and regulatory requirements for floating facilities. The spar hull was fabricated in Finland and traveled to the gulf coast by dry transport. There it was outfitted and then wet towed to Keathley Canyon Block 875 in preparation for upending and mooring installation in 7,100 ft of water. The offshore campaign for the installation of the hull and mooring system was successfully completed in October of 2013 in preparation for the Topsides set in February of 2014. This paper summarizes the design and fabrication of the Lucius spar as well as exploring the project challenges for the delivery and installation of the facility, with special attention given to the issue of safety. The Lucius Spar is the operator’s largest spar to date and uses the latest technology to moor the hull in very

864 ABSTRACTS

challenging terrain. The installation contractor for the hull and mooring system provided extensive engineering and project management to plan and execute the installation safely.

Fabrication Installing Offshore platforms Platform design

2015102328

Ship-based carbon dioxide capture and storage for enhanced oil recovery. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25861 [14 p] https://www.onepetro.org/conference-paper/OTC-25861-MS Ozaki, M., Nakazawa, N., Et al English

This paper presents details of a proposed ship-based carbon dioxide capture and storage (CCS) method. CCS is one of the key technologies essential to achieve greenhouse gas reduction. This technology can also contribute to enhanced oil recovery (EOR) efforts by increasing oil production in mature fields. The liquefied CO2 (LCO2) to be sequestered is injected directly into subsea bed geological formations through a flexible riser pipe using injection facilities contained onboard an LCO2 carrier ship. The primary characteristics of this LCO2 subsea bed injection system are as follows: the presence of LCO2 injection equipment onboard the LCO2 carrier ship, a direct injection into subsea bed geological formations through a flexible riser pipe, and the absence of any stationary sea surface structures at the offshore CO2 injection site. The advantage of ship-based transportation is flexibility in regard to i) multiple CO2 shipping locations and storage sites, ii) multiple injection sites from a large CO2 storage port, and iii) relocation of the injection site resulting from either termination of oil production or the site becoming filled with CO2. That is, ships can easily alter their shipping ports and routes to the offshore injection site(s), depending on requirements.

Carbon dioxide Injection Liquefied gases Ships Storage

2015102329

Stationkeeping technology for frontier deepwater floating systems. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26058 [19 p] https://www.onepetro.org/conference-paper/OTC-26058-MS Duggal, A.S., Izadparast, A.H., Pothuganti, V.K. English

This paper provides an overview of the challenges associated with the stationkeeping of floating systems in frontier deepwater, and the range of solutions to address them. The paper presents the use of existing technologies, materials and components, and compare and evaluates them to the use of novel materials, new and possibly not field proven technologies, and design approaches. The paper provides a high-level design basis and strategies for the stationkeeping system design, identifying key drivers in the selection of the stationkeeping system. The paper then utilizes an example of an FPSO system moored in a range of water depths to illustrate the current capabilities of conventional technologies and strategies to improve performance.

Deepwater Floating production systems FPSOs Stationkeeping

2015102330

Technical challenges and impacts of extending spar and semisubmersible platform capabilities to 4,500 m water depth. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25836 [19 p] https://www.onepetro.org/conference-paper/OTC-25836-MS D’Souza, R.B., Aggarwal, R., Subramanian, R. English

Spar and semi-submersible platforms are proven deepwater production platforms. They have been used extensively in the Gulf of Mexico (GoM) to produce large deepwater developments. Spars have progressed from 600 m to 2,600 m water depth since 1995 and semi-submersibles from 450 m to 2,500 m since 1985. Topsides and hull sizes have grown to accommodate increasingly larger topside, riser, and mooring payloads. Extending these platforms to 4,500 m represents an almost 80% increase in water depth. The main technical challenges relate to the

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technical feasibility and installation of risers and mooring systems and their impact on the size and global performance of the hulls. Both aspects are examined in this paper for applications in the GoM. The first aspect addresses technical challenges associated with designing production, injection, and export risers to handle the large hydrostatic pressure and limitations and/or gaps with regard to current lay vessel capabilities to install risers in 4,500 m water depths. The second aspect addresses the relative sensitivity of hull sizes and global performance of semi-subs and spars at these water depths for a common topsides and subsea architecture basis of design. This paper presents the impact of extending design, fabrication, and installation of spar and semi-sub floating platforms to 4,500 m water depth. Field development scenarios, design basis and topside parameters (load, area, and height) are used to size hull, mooring, and risers to define the overall system. Proven, conventional hull designs and sub-systems technologies are used for both 2,500 m and 4,500 m water depths. Platform sizes and global responses in 2,500 m and 4,500 m water depths are compared. Technology gaps in meeting basis of design are identified. Trends, observations and relative sensitivities of the hull forms are captured. Enhancing and enabling technologies for risers and moorings are discussed. The 4,500 m hull sizes and key dimensions are compared with existing platforms to address availability of yards and vessels for construction and installation phases. Challenges related to fabrication, topside integration, mooring and risers installation in 4,500 m water depth for the two hull types are also addressed and contrasted.

Deepwater Offshore platforms Semisubmersibles

2015102331

Wave energy conversion: opportunity, challenges, and design considerations. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 26024 [16 p] https://www.onepetro.org/conference-paper/OTC-25992-MS McCall, A., Clabby, D. English

This paper reviews the state of Wave Energy Conversion (WEC) technology as it relates to the ASCE COPRI Marine Renewable Energy (MRE) Committee's efforts to study and disseminate information on marine renewable energy facilities. Of

particular interest are topics within the field related to risk and reliability aspects of WECs, the opportunity of devices within the field of Wave Energy, and how moorings requirements differ from device to device. A set of WEC device types, including the predominant technologies such as: point absorber, attenuator, and surge converter type devices, as well as emerging device types will be reviewed at a high level. Each device type will then be investigated to understand which aspects are most critical to performance, risk and reliability. These devices will also be examined for the links between performance and the role of moorings, drawing out the relationship between each device and its mooring requirements. This paper will result in a clear understanding of the current WEC landscape with respect to how each device type potentially fits into the industry. Specific outcomes will include: An overview of some of the most significant device types, new and alternative device types, important design considerations for both performance and reliability, and the relationship between each device and its mooring.

Wave energy conversion

2015102332

Alternative method for estimation of design extremes for moored floaters. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23832 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912076 Bonnaffoux, G., Melis, C. English

After having relied for decades totally on small scale model tests, the design of anchoring systems for moored floaters like FPSOs is now widely performed numerically. Estimation of design maxima during mooring analyses requires calculating system response for a large number of sea states in order to screen all possible scenarios between wind, waves and current parameters. In addition, the slow-drift response motions of the system constituted by the floater and the anchoring system are highly dependent of the wave elevation realization, which is not an input parameter of the simulations and can lead to extremely variable responses. This is generally addressed by designers by performing the analysis for the same sea state and varying the wave group spectrum (or wave components phases) a large

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number of times N (20–50 realizations is a typical range. For these N realizations, N response maxima are extracted, and a distribution of response extremes is derived, from which the response level is extracted. In terms of computational cost, performing N 3-hour simulations to derive N values of extreme response is extremely expensive. The paper focuses on methods that can be employed to reduce the computational cost of analyses. In a first step, the rapidity of statistical convergence of response estimates depending on the system is investigated. This will allow pre-determining the number of sea states realizations required to reach a satisfactory convergence of response. In a second step, a mean of improving the computational efficiency of calculations carried-out to reach the statistical convergence is proposed.

Design Floating structures Mooring systems Numerical analysis Sea state

2015102333

Stochastic space-time extremes of wind sea states: validation and modelling. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23997 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912090 Barbariol, F., Benetazzo, A., Et al English

Damage and accidents to offshore structures and ships raise questions about adequacy of conventional time domain analysis of short-crested sea waves. Indeed, experimental and field evidence showed that during such wave states, typical of storms, the maximum sea surface elevation gathered at a single point in time, i.e. the time extreme, tends to underestimate the actual maximum that occurs over a surrounding area, i.e. the space-time extreme. Recently, stochastic models for the prediction of multidimensional Gaussian random fields maxima, e.g. Piterbarg’s theorem and Adler and Taylor’s approach, have been applied to ocean waves statistics, permitting to extend extreme value analysis from time to space-time domain. This paper presents analytical and numerical approaches aimed at supporting applicability of such models, which is limited by the

knowledge of directional spectrum parameters. Firstly, the authors validate stochastic models against stereo-photogrammetric measurements of surface wave fields. Then, they investigate the dependence of space-time extremes upon physical parameters (wind speed, fetch length, current speed) in the context of analytical spectral formulations, i.e. Pierson-Moskowitz and JONSWAP, and by using spectral numerical wave modelling. To this end, two sets of closed formulae and a modified version of the SWAN model are developed to calculate parameters of analytical and arbitrary directional spectra, respectively. Finally, preliminary results are presented of a 3 years Mediterranean Sea hindcast as a first step towards operational forecasts of space-time extremes.

Ocean waves Stochastic processes Wind

2015102334

Spar platform installation: tank flooding simulation. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24328 [5 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912118 Medellin, A., Arango-Turner, M., Fuhr, C. English

Spars are towed to installation site horizontally and upended by progressive flooding of tanks. It is common practice to perform a dynamic time domain simulation for a self-upending classic spar to determine hydrostatic pressures on compartments. There are many different flooding scenarios that create challenges in modelling and simulation during the design phase. In one particular scenario, the spar upending is initiated by opening valves that allow water to flood into the skirt tank. The skirt tank will progressively fill, based on the differential hydrostatic pressure at valves, and cause the spar to upend. Flooding into keel tanks will commence once respective openings become submerged. Several openings from the skirt tank into the keel tanks reduce the differential pressure experienced in the keel tanks during upending. Simulation of the transfer of water between tanks cannot be modelled with ease using the standard tank flooding options available within the software suite. This particular

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compartment flooding problem is solved by utilizing a scheme in which the time domain simulation was performed iteratively for a specified time interval. For every iteration the amount of water transferred between the skirt and keel tanks are calculated. The amount of water transferred is calculated using a custom modelling technique. The openings from the skirt tank into the keel tanks are not modelled as a typical hole or valve into a compartment, but the location of these holes are modelled. The amount of water flowing through these openings is determined by the water level in the skirt tank, friction through the opening, and pressure inside the keel tanks. This paper describes in detail the scheme developed, the tank modelling requirements, and the results obtained.

Flooding Installing Offshore platforms Tanks

2015102335

Numerical assessment on primary wave energy conversion of oscillating water columns. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4553-0. Volume 9A: Ocean Renewable Energy. Paper No. OMAE2014-23218 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912148 Sheng, W., Alcom, R., Lewis, T. English

Oscillating water column (OWC) wave energy converters (WECs) are probably the simplest and most promising wave energy converters due to their good feasibility, reliability and survivability in practical wave energy conversions and also regarded as the most studied and developed when compared to other types of the wave energy converters. This research aims to develop a reliable numerical tool to assess the performance of the OWC wave energy converters, particularly in the primary wave energy conversion. In the numerical assessment tool, the hydrodynamics of the device and thermodynamics of the air chamber can be studied separately. However, for the complete dynamic system when a power take off (PTO) system is applied, these two dynamic systems are fully coupled in time-domain, in which the PTO can have a simple mathematical expression

as the relation between the pressure difference across the PTO (the chamber pressure) and its flowrate through the PTO. And the application of a simple PTO pressure-flowrate relation very much simplifies the complicated aerodynamics and thermodynamics in the air turbine system so the whole dynamic system can be simplified. The methodology has been applied to a generic OWC device and the simulation results have been compared to the experimental data. It is shown that the developed numerical method is reliable in and capable of assessing the primary wave energy conversion of oscillating water columns.

Numerical analysis Performance Wave energy conversion

2015102336

Accurate estimation of the 100-year responses from the probability distribution of extreme surface elevations. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24589 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911696 Mallahzadeh, H., Wang, Y., Et al English

Accurate estimation of the 100-year responses (derived from the long-term distribution of extreme responses) is required for the safe and economical design of offshore structures. However, due to nonlinearity of the drag component of Morison’s wave loading and also due to intermittency of wave loading on members in the splash zone, the response is often non-Gaussian; therefore, simple techniques for derivation of the probability distribution of extreme responses are not available. To this end, conventional Monte Carlo time simulation technique could be used for predicting the long-term probability distribution of the extreme responses. However, this technique suffers from excessive sampling variability and hence a large number of simulated response records are required to reduce the sampling variability to acceptable levels. This paper takes advantage of the correlation between extreme responses and their corresponding extreme surface elevations to derive

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the values of the 100-year responses without the need for extensive simulations. It is demonstrated that the technique could be used for both quasi-static and dynamic responses.

Dynamic response Offshore structures Probability distribution functions

2015102337

Transferring wave conditions from offshore to nearshore: the case of Nordfold. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24613 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911699 Stefanakos, C.N., Eidnes, G. English

In this work, an analysis of the wave climate in Nord-fold area in the northern Norway has been performed. The analysis was carried out by transferring offshore wave conditions to the nearshore area of interest by successive applications of the well-known third-generation wave model SWAN. The area presents a particular interest, since it has a very deep and complex bathymetry near the coast and a very complicated coastline. Analysis has been carried out using a very detailed bathymetry of the area provided by the Norwegian Mapping Authority. Moreover, as input, five year long time series of directional spectra of offshore wave parameters have been used, after being calibrated using the best available satellite altimeter dataset.

Inshore Offshore Wave climate Wave models

2015102338

Probabilistic red limit study for mobile offshore drilling units. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24614 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911700 Gjerde, T., Chen, H. English

More and more mobile offshore drilling units (MODUs) are equipped with dynamic positioning (DP) system to maintain vessel position during drilling and well operations. A failure in the DP system might in worst case lead to position loss in terms of drive-off or drift-off. In a position loss scenario, the operator needs to activate the emergency disconnect sequence (EDS) of the marine riser at the time when the vessel reaches a site specific critical distance, denoted the red limit. The red limit distance takes into account the time it takes for the EDS sequence to complete, in addition to the vessel position loss speed and the physical excursion limit for the marine riser, BOP and wellhead system. The red limit is a site-specific parameter, which is dependent on many factors. This paper presents an alternative probabilistic methodology to determine the red limit based on probabilistic modelling of position loss scenarios, using a case study of DP class 3 drilling vessels at specific well sites and environmental conditions.

Dynamic positioning Failure Mobile platforms Probabilistic methods

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2015102339

On variability of mean wave direction during severe storms. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24633 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911701 Laface, V., Arena, F., Guedes Soares, C. English

The paper deals with the directional analysis of severe storms in some European locations, in the Atlantic Ocean and North Sea. The analysis is carried out by considering significant wave height and wave direction time series, from the HIPOCAS project database. At each considered location, all storms in the data set are identified. Then, for each storm, variability of direction during sea states is investigated. The results of this analysis show how direction during storms varies within well-defined sectors identified from the main directions from which the strongest storms occur plus or minus a certain angle Δϑ, and from one or more secondary sectors. The variation of direction during storms is evaluated in terms of standard deviation of direction, either by considering all sea states during storm or only sea states during the part of the storm above a fixed threshold h of significant wave height. The results show that standard deviation of direction decreases as the threshold h increases and it is due to the fact that variability of direction near the storm peak is smaller than in the full storm.

Storms Variability Wave direction

2015102340

Ageing accidents: suggestion for a definition and examples from damaged platforms. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4545-5. Volume 5: Materials Technology; Petroleum Technology. Paper No. OMAE2014-23674 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911741 Ersdal, G., Sharp, J., Galbraith, D. English

An increasing number of offshore installations are in the life extension stage of life, resulting in a growing concern among structural engineers about ageing related issues. However, structural engineers are often asked if there is experience of any ageing accidents or if there are examples of such. A safety conscious person would then reply that theory points towards a growing failure rate and hence that ageing accidents will eventually occur. Good engineering practice would then imply that there is no point in waiting for the accident to occur. As responsible engineers we should investigate the hazards and avoid accidents without having to wait for a potentially fatal accident to lead to action. The other possible answer is to question the term “ageing accident”. What is the definition of an “ageing accident”? This investigates into the term “ageing accident” and proposes a definition of this term. Further, this paper describes some examples of ageing accidents, in particular the many structural failures that have occurred in the Gulf of Mexico hurricanes.

Ageing offshore structures Platform accidents

2015102341

Study of vessel-offshore installations collision and blowout accidents with the assistance of the Meta-analysis method. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [12 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=0e5a590c-208e-4c49-8e82-a488211b8030 Ventikos, N., Grammatikaki, A. English

Offshore structures and related accidents are discussed in this article. In the first part, concrete information regarding oil and gas installations is

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provided and in the second part, the vessel-platform collision and blowout accidents are studied with the assistance of the Meta-analysis method. Particularly, two meta-analyses were conducted; each one for collision and blowout accidents. The first meta-analysis examined the possible relationship between the type of installation and the severity of a collision accident among specific types of installations and vessels. It was found that a severe collision accident is equally possible at any platform type. The second meta-analysis evaluated the possibility of a severe blowout in correlation with the exploitation phase. It concluded that a well can suffer a severe blowout at any point of an exploitation phase. The survey was conducted with the objective to minimize the risks of offshore accidents with heavy impacts.

Blowouts Offshore structures Platform accidents Platform rammings

2015102342

Developing a risk analysis and decision making strategy for an offshore wind farm. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [8 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=37890399-08f5-40aa-bce0-ae69c13ed8e6 Kougioumtzoglou, M.A., Lazakis, I. English

The renewables sector and particularly offshore wind energy is a fast developing industry. Especially activities related to the installation, Operation and Maintenance (O&M) of offshore wind turbines becomes a challenging task with inherent risks. This paper assesses the risks related to the above stages of a wind farm lifecycle using the Failure Mode, Effects and Criticality Analysis and Hazard Identification methods. The full-scale offshore installation and O&M tasks are considered together with the wind turbine main components. An integrated risk analysis methodology is presented addressing personnel safety, environmental impact, asset integrity and Operation. The above is supplemented by a cost analysis with the aid of Bayesian Belief Networks

method in order to assist the decision making process related to installation and O&M tasks. All major risks and critical wind turbine components are identified as well as measures are suggested in order to prevent or mitigate them. Moreover, a thorough inspection and maintenance plan can be elaborated for the mentioned activities.

Risk analysis Wind turbines

2015102343

Numerical simulation of multi-body wave point-absorber. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 80 [8 p, 9 ref, 1 tab, 16 fig] https://www.crcpress.com/product/isbn/9781138027893 Li, L., Tan, M., Blake, J.I.R. English

Multi-body wave energy converter is being considered to be one of harvest technologies to maximize the potential to extract the renewable source of energy from the ocean. The key issues in this field are to understand the interaction between bodies; and develop the awareness of how to utilize the impact of these. This paper describes a set of numerical simulations designed to investigate the optimum configuration of a simple two-body point absorber device. Deep-water condition is applied and regular surface waves are used to describe the ocean waves. The single point-absorber system is modelled as two independently moving bodies connected to a direct driven linear generator and the generator is simplified as a spring-damping system. The results confirm that the ability to extract energy depends on the mass and geometry of the moving parts, together with the damping of generator. It is also demonstrated that the outcome is sensitive to the distance between the two moving bodies and local wave condition.

Multibody systems Numerical models Wave absorbers Wave energy conversion

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2.7 SAFETY AT SEA

2015102344

Safety first. Marine Log, v 120 n 6, June 2015, p 39 [2 p, 10 fig] http://issuu.com/marinelog/docs/june_2015_marine_log/1?e=5112807/13455705 Morter, P. English

By utilizing all the available data relating to a collision incident, BMT ARGOSS and BMT Surveys, subsidiaries of BMT Group Ltd, the leading international design, engineering and risk management consultancy, have partnered to use the REMBRANDT ship manoeuvring simulator as part of the maritime casualty investigation process. The newly formed Collison Reconstruction and Simulation Team will be able to accurately reconstruct specific incidents involving collisions in order to identify the root cause and any lessons that can be learned. BMTs team, which includes experienced master mariners, chief engineers, navigation and hydrodynamic modellers and weather experts, has the essential skills, depth of maritime knowledge and crucial technology to reconstruct incidents using a visual format and readily understandable process. The simulation uses shipboard Voyage Data Recorder (VDR) data, radar images and regional AIS information combined with high fidelity ship models, which can be re-modelled to required parameters, to produce meaningful three-dimensional simulations. Voice, radar and position data sets are automatically synchronised, together with environmental data and navigational circumstances, to present a complete and seamless reconstruction of events for in depth analysis. Combining the highly accurate simulation with the skilful analysis of marine experts, failings can be identified to create an unbiased appraisal of how and why an incident has occurred. The resulting incident reconstruction can be used to identify what happened not only for litigation purposes, but to help improve maritime safety. Once the root cause is determined the first steps towards future prevention can be implemented. This knowledge and also the liaison with the client can produce a range of what if

scenarios that can be thoroughly investigated and evaluated to produce specific training needs, valuable lessons and operational policies and procedures. These results can be implemented to create a cost effective and safe approach to assist in the prevention of marine collisions and casualties.

Accident investigations Ship simulators Voyage data

2015102345

Performance of overall heat transfer coefficient and exploring heat transfer through the ceiling vent of compartment fire in ship structures with A60 constructions. Ships and Offshore Structures, v 10 n 3, June 2015, pp 328-334 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.876166#.VYfaS03JCUk Zhang, J., Lu, S., Et al English

Exploratory investigations on overall heat transfer coefficient of compartment fires in ship structures with A60 constructions were conducted, as well as heat transfer through ceiling vented compartments in such constructions. The results indicated that the overall heat transfer coefficient decreased with the burning process, as well as the cooling process after the extinction. From the view of temperature difference, the overall heat transfer coefficient decreased exponentially with the rising temperature difference for “temperature rise” stage, and increased linearly with the increase of the temperature difference for “temperature drop” stage. For the tested cabin, the average overall heat transfer coefficient was in proportion to one-third power of the heat release rate. In addition, care should be taken in applying Cooper algorithm to calculate the mass flow out of the ceiling vented compartment for fires directly beneath the ceiling vent, under which the plume-induced flow may be the dominant factor under such circumstance. Finally, a potential method was suggested to deal with the ceiling vent flow for fires positioned directly under the ceiling vent.

Accommodation spaces Heat transfer Shipboard fires

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2015102346

The impacts of the safety culture in oil and gas operations. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25883 [8 p] https://www.onepetro.org/conference-paper/OTC-25883-MS Floris, V.V. English

Safety culture is defined as a system comprised of values, norms, competencies, attitudes and patterns of behavior that determines the commitment, style and proficiency of an organization's safety performance. This paper describes the complexity of oil and gas operations, and points that a weak safety culture could produce severe individual or organizational incidents with catastrophic consequences. This paper introduces a Safety Maturity Matrix (with a focus on the oil and gas industry) which explains the path from the pathological stage to the generative (top) level. This model brings together all the elements of a safety culture to achieve and sustain an environment that evolves with ever-changing techniques and challenges.

Gas industry Petroleum industry Safety

2015102347

Investigation of oil tanker accidents by using GIS. RINA Transactions - IJME - v 157 part A2, April-June 2015, p 113 http://www.rina.org.uk/ijme.html Uğurlu, Ö., Yildirum, U., Et al English

This study focuses on marine accident data regarding accidents that occurred between the years 1998-2010 for ships within the oil tanker category. Data in the study include accident reports, which are recorded in the Global Integrated Shipping Information System (GISIS) and country reports. Textual accident data in the GISIS database were tabulated, thus creating a systematic database. By using accident data from this database, a marine accidents map for oil tankers was developed via the ArcGIS 10 program, the areas with the highest accident incident rates were determined, and reasons for oil tanker accidents were revealed through the assessment of factors such as accident

type, accident incident number, accident scope, ship tonnage, navigational sea area type, and accident’s impacts on the environment, economy and personnel. The study showed that very high risk areas for oil tanker marine accidents include the Singapore Strait and Oresund, and high risk areas are the Bristol Channel, Suez Channel, Strait of Hormuz, Great Belt, Piraeus, Hull, İstanbul Strait, and Amsterdam, respectively. The study also established that oil tanker accidents are related to ship tonnage and navigational sea area type.

Accident research Oil tankers Risk analysis Tanker accidents

2015102348

Effects of wind strength and wave height on ship incident risk: Regional trends and seasonality. Transportation Research Part D: Transport and Environment, v 37 June 2015, pp 29-39 http://www.sciencedirect.com/science/article/pii/S1361920915000486 Heij, C., Knapp, S. English

Oceanographic conditions like wind strength and wave height affect the risk of shipping incidents. Seasonal variations and trends in these effects are studied for weather-related incidents and pollution incidents, for six major ship types and for six regions across the globe. The employed database of more than five million observations combines information from various sources on oceanographic conditions, ship particulars, and incidents. The magnitude of wind and wave effects is found to vary by ship type, region, season, and period, and most of these effects are larger during the autumn and winter season and in recent periods.

Marine accidents Oceanographic data Risk analysis Wave height Wind conditions

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2015102349

Effect of wind loads on the performance of free-fall lifeboats. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24456 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911685 Sauder, T., Croonenborghs, E., Et al English

The paper presents a model describing the launch of free-fall lifeboats from offshore structures in strong environmental wind. Six-degrees-of-freedom numerical simulations of the lifeboat launch are performed using the free-fall lifeboat simulator VARUNA with a complete set of wind coefficients for the lifeboat. Those wind coefficients are obtained by CFD simulations validated against wind tunnel tests. The lifeboat launch simulations are then verified against time-domain CFD simulations of the whole launch in air until water entry. It is shown by means of numerical simulations that wind-induced loads on the lifeboat have a strong influence on its kinematics until water entry, and subsequently on the acceleration loads experienced by the occupants, on the structural loads on the lifeboat, and on its forward speed after water exit. It is concluded that the effect of wind-induced loads on the lifeboat performances should in general be investigated when establishing the operational limits for a given offshore installation.

Launching Lifeboats Offshore structures Wind loads

2015102350

Norwegian work on search and rescue in Barents Sea. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4556-1. Volume 10: Polar and Arctic Science and Technology. Paper No. OMAE2014-24402 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912299 Dyrkoren, E., Berg, T.E. English

Increased shipping and offshore activities in the

Barents Sea need improved emergency response capability in Norway and Russia. In both countries there are several projects and initiatives that aim towards mitigating the consequences from small accidents and larger catastrophes, some coordinated across borders, others not. This paper aims towards giving an overview of the current and near future state of emergency response in the Barents Sea. First the emergency response preparedness that is fully operational today is described. Then a brief description is given of operations and activities we see today and in the foreseen future, and types of challenges and risks associated with them in this particular environment are discussed. Using this as a background, the paper looks at Norway’s ambitions for future search and rescue preparedness in the Norwegian Arctic waters and the ways emerging technologies can improve emergency response operations. Finally some recommendations are given on what needs to be done by Norway, Russia and the industrial operators in order to achieve an improved level of emergency response preparedness.

Barents Sea Emergencies Emergency response systems Search and rescue

2015102351

Statistics of collision, grounding and contact accidents of passenger and container ships. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [10 p, 12 ref, 17 tab, 13 fig] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=78eae9b9-ef7d-4ae8-bf6f-69ef84ae1f8c Pagiaziti, A., Maliaga, E., Et al English

The main objective of this paper is to present the results of the analysis of collected data from accidents to passenger ships and container ships. The accident types that have been considered are collision, grounding and contact. The developed databases are aimed to provide the necessary data to serve the following two distinct objectives: The development of a quantitative risk model for the damage stability related risk to human life associated with collision and grounding accidents to passenger ships and the development of a probabilistic model for the damage

874 ABSTRACTS

characteristics, in the form distribution functions for the location and extend of a breach, as a result of a grounding accident.

Containerships Groundings Passenger ships Risk Ship collisions

2.8 ENVIRONMENTAL PROTECTION

2015102352

Recovery from TBT pollution in English Channel environments: A problem solved? Marine Pollution Bulletin, v 95 n 2, 30 June 2015, pp 551-564 http://www.sciencedirect.com/science/article/pii/S0025326X14008121 Langston, W.J., Pope, N.D., Et al English

Following recognition of effects in the 1980s, tributyltin (TBT) has been monitored at sites in the English Channel to evaluate the prognosis for biota – spanning the introduction of restrictions on TBT use on small boats and the recent phase-out on the global fleet. The authors describe how persistence and impact of TBT in clams Scrobicularia plana has changed during this period in Southampton Water and Poole Harbour. TBT contamination (and loss) in water, sediment and clams reflects the abundance and type of vessel activity: half-times in sediment (up to 8y in Poole, 33y in Southampton) are longest near commercial shipping. Recovery of clam populations – slowest in TBT-contaminated deposits – provides a useful biological measure of legislative efficacy in estuaries. On rocky shores, recovery from imposex in Nucella lapillus is evident at many sites but, near ports, is prolonged by shipping impacts, including sediment legacy, for example, in the Fal.

Antifouling coatings English Channel Environmental effects Environmental protection

2015102353

Regionalized risk assessment of accidental tanker spills using worldwide data. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [10 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=0053a256-163b-4f5d-8d11-40683a4fcb64 Burgherr, P., Spada, M., Kalinina, A. English

This study analyses the risk of accidental oil spills from tankers. It builds upon the historical experience available in the Energy-related Severe Accident Database (ENSAD), covering the period 1970-2012. Global and regional spill risk was evaluated, using a four-step approach. First, a threshold analysis using maximum likelihood estimation was carried out to determine the effect of the minimal spill size considered in subsequent analysis. Second, different probability distribution functions were fitted separately to the spill frequency and severity data to identify the best model to parameterize the historical observations. Third, the expectation of an extreme spill was tested by means of a Bayesian analysis. Fourth, regionalized spill indicators were calculated to compare and prioritize risk across regions, but also to identify potential hotspots. In conclusion, this kind of top-down risk assessment can support decision making processes.

Oil spills Spill risk Tanker accidents

2015102354

Bayesian inference-based environmental decision support systems for oil spill response strategy selection. Marine Pollution Bulletin, v 96 n 1-2, 15 July 2015, pp 87-102 http://www.sciencedirect.com/science/article/pii/S0025326X15002982 Davies, A.J., Hope, M.J. English

Contingency plans are essential in guiding the response to marine oil spills. However, they are written before the pollution event occurs so must contain some degree of assumption and prediction and hence may be unsuitable for a real incident when it occurs. The use of Bayesian networks in ecology, environmental management, oil spill contingency planning and post-incident analysis is reviewed and

ABSTRACTS 875

analysed to establish their suitability for use as real-time environmental decision support systems during an oil spill response. It is demonstrated that Bayesian networks are appropriate for facilitating the re-assessment and re-validation of contingency plans following pollutant release, thus helping ensure that the optimum response strategy is adopted. This can minimise the possibility of sub-optimal response strategies causing additional environmental and socioeconomic damage beyond the original pollution event.

Bayes theorem Decision support systems Oil spills Pollution response systems

2015102355

Marine oil spill risk mapping for accidental pollution and its application in a coastal city. Marine Pollution Bulletin, v 96 n 1-2, 15 July 2015, pp 220-225 http://www.sciencedirect.com/science/article/pii/S0025326X15002805 Lan, D., Liang, B., Et al English

Accidental marine oil spill pollution can result in severe environmental, ecological, economic and other consequences. This paper discusses the model of Marine Oil Spill Risk Mapping (MOSRM), which was constructed as follows: (1) proposing a marine oil spill risk system based on the typical marine oil spill pollution accidents and prevailing risk theories; (2) identifying suitable indexes that are supported by quantitative sub-indexes; (3) constructing the risk measuring models according to the actual interactions between the factors in the risk system; and (4) assessing marine oil spill risk on coastal city scale with GIS to map the overall risk. The case study of accidental marine oil spill pollution in the coastal area of Dalian, China was used to demonstrate the effectiveness of the model. The coastal areas of Dalian were divided into three zones with risk degrees of high, medium, and low. And detailed countermeasures were proposed for specific risk zones.

Coastal regions Oil spills Spill risk

2.9 GENERAL OPERATION

2015102356

Estimating the carbon footprint of Tasmanian fishing vessels. RINA Transactions - International Journal of Small Craft Technology, v 157 Part B1, January-June 2015 http://www.rina.org.uk/ijsct.html Floyd, H., Chin, C.K.H., Et al English

Life cycle assessments (LCA) are conducted to understand the environmental impacts associated with various products. In order to convey quality information to the consumer that can be guaranteed to provide comparability between products and ease of communication, the PAS 2050 specification produced by the British Standards Institute was utilised. The functional unit assigned to the calculation of the carbon footprint was one kilogram of edible yield delivered to the distribution centre. This paper aims to demonstrate the implementation of a LCA for the Tasmanian scallop fishery by analysing two fishing operations within the industry. The final value for the assessments were 3.16 kg carbon dioxide equivalent (CO2e) and 2.19 kgCO2e for vessel A operating in the Bass Strait and the eastern Tasmania fishing zone respectively, while vessel B had a final value of 3.89 kgCO2e.

Estimating Carbon dioxide Fishing vessels

2015102357

Technoeconomic evaluation of energy efficiency retrofits in commercial shipping; a bulk carrier case study. 4th International Symposium on Green Chemistry for Environment, Health and Development; 24-26 September 2014; Kos Island, Greece. Organized by the Society of Ecotoxicology & Environmental Safety and the Department of Planning and Regional Development, University of Thessaly. [9 p, 22 ref, 5 tab, 2 fig] http://www.greenchem4.prd.uth.gr/index.html Tsereklas-Zafeirakis, A., Aravossis, K., Et al English

This study approaches the maritime sector from an environmental point of view. In light of the new IMO directives on climate change and the continuous effort to reduce operating costs, this paper investigates the viability of several energy efficiency technologies.

876 ABSTRACTS

The introductory part discusses the environmental problem caused by the gaseous pollutants and describes the existing and future regulatory framework that either has been or will be imposed in order to mitigate the impact of the shipping industry. In the main part, a series of fifteen energy efficiency retrofits, suggested by IMO, are briefly analysed with a view to applying them on a bulk carrier. This analysis conducts a techno-economic evaluation of these retrofits as potential investments from an owner’s strategic point of view. The assessment, taking into account major uncertainties of the data used, concludes that the vast majority of methods prove to be initially acceptable for investment.

Bulk carriers Economic analysis Efficiency Energy conservation Retrofitting

2015102358

Special consumption tax incentive on marine bunkers and cargo shifting to short sea shipping in Turkish cabotage routes. RINA Transactions - IJME - v 157 part A2, April-June 2015, p 85 http://www.rina.org.uk/ijme.html Kilic, A., Girit, O. English

Some gases such as methane (CH4) and carbon dioxide (CO2) which are called as greenhouse gases (GHGs) are seen as the most important causes of global warming. Harmful exhaust gases and CO2 emissions arise from burning fossil fuels on board. Maritime transportation is the most efficient mode when compared to other modes. However, Turkey's passenger and cargo transportation mainly depends on road transportation which has high fuel costs compared to sea transportation. In this study, by evaluating cabotage bunker fuels, annual CO2 emissions from maritime ships sailing on Turkish cabotage line were investigated. Also fuel efficiency of maritime transport as well as the effects of shifting cargo between transportation modes on CO2 emissions was analysed.

Coastal shipping Emissions Exhaust gases Fuel costs Short sea trades

2015102359

A bond graph approach to improve the energy efficiency of ships. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24026 [ 9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912095 Jafarzadeh, S., Pedersen, E., Et al English

High fuel consumption coupled with increasing fuel prices, emission regulations and increasing concern about the environment, act as incentives to reduce the energy consumption of ships. However, different barriers hinder the adoption of cost-effective energy saving measures by ship owners and operators. These barriers are the reason for the existence of an ‘energy efficiency gap’ between the current level of energy efficiency and the potential for development of higher order efficiency. Imperfect information regarding the current level of energy consumption of vessels, availability and application of energy saving measures, and the impact of adopting these measures, form a group of so called ‘information barriers’. The main objective of this paper is to reduce those information barriers, as faced in shipping and more specifically in the fishing sector. The bond graph methodology is presented as a potential solution to these issues. It is utilized as a modelling and simulation method by which to visualize energy flow in a fishing vessel. The bond graph method is employed to estimate the fuel consumption of the vessel under different operational conditions: steaming, trawling and hauling of the fishing gear. It is also applied in pinpointing the major energy consuming apparatuses onboard the vessel. In this way knowledge regarding the current levels of energy consumption can be increased. The main energy consumers can then be studied to further improve energy efficiency knowledge and subsequently reduce the energy efficiency gap of the fishing vessel. Finally, the effectiveness of implementing a slow steaming strategy as a possible energy saving mechanism is studied.

Efficiency Energy conservation Energy consumption Graphic methods

ABSTRACTS 877

2015102360

Effect of ship speed on level ice edge breaking. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24101 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912106 Sazidy, M., Daley, C., Et al English

This paper presents a numerical model of ship ice-wedge interaction to study the effect of ship speed on level ice edge breaking. The interaction process is modelled using LS-DYNA. The developed model considers ice crushing, ice flexural failure and the water foundation effect. For the ice, two different plasticity-based material models are used to represent ice crushing and ice flexural behaviours. The water foundation effect is modelled using a simple linear elastic material. The analysis is performed for a ship speed range of 0.1 to 5 ms−1 and ice thickness of 0.5 to 1.5 m. The analysis indicates that both ship speed and ice thickness significantly affect the ice breaking process. The model results are in good agreement with a number of analytical and empirical models. The model can be useful in establishing a rational basis for safe speed criteria, improving ship structural standards and tools for ice management capability assessment.

Icebreaking Numerical analysis Ship speed

2015102361

A bi-objective approach to routing and scheduling maritime transportation of crude oil. Transportation Research Part D: Transport and Environment, v 37 June 2015, pp 65-78 http://www.sciencedirect.com/science/article/pii/S1361920915000425 Siddiqui, A.W., Verma, M. English

Maritime transportation, the primary mode for intercontinental movement of crude oil, accounts for 1.7 billion tons annually - bulk of which are carried via a fleet of large crude oil tankers. Although spectacular episodes such as Exxon Valdez underline the significant risk and tremendous cost associated with marine shipments of hazardous materials, maritime literature has focused only on the cost-

effective scheduling of these tankers. It is important that oil transport companies consider risk, since the insurance premiums is contingent on the expected claim. Hence through this work presents a mixed-integer optimisation program - with operating cost and transport risk objectives, which could be used to prepare routes and schedules for a heterogeneous fleet of crude oil tankers. The bi-objective model was tested on a number of problem instances of realistic size, which were further analysed to conclude that the cheapest route may not necessarily yield the lowest insurance premiums, and that larger vessels should be used if risk is more important as it enables better exploitation of the risk structure.

Crude oil Oil transportation Scheduling Ship routing Tankers

2015102362

The development of a decision making framework for evaluating the trade-off solutions of cleaner seaborne transportation. Transportation Research Part D: Transport and Environment, v 37 June 2015, pp 150-170 http://www.sciencedirect.com/science/article/pii/S1361920915000553 Ölçer, A., Ballini, F. English

The general rise in marine fuel prices in combination with ever-more stringent environmental regulations resulting from IMO conventions and EU Directives have become the main industry drivers for seaborne transportation to become cleaner and more energy efficient. Compliance with existing and soon-to-be-enacted regulations requires evaluating the trade-off between often-conflicting options to select the best available technology or fuel source. Although the traditional way of dealing with this issue has been to apply a cost benefit analysis, this kind of analysis does not adequately consider the complexities of the problem, such as incorporating linguistic preferences or interrelations amongst attributes, experts and their preferences. The challenge in such an analysis corresponds to that of a multiple attribute decision-making problem in which a finite number of alternatives are assessed with regards to a finite number of attributes and experts and ranked from the best to the worst. In this paper, a comprehensive and holistic decision-making framework is proposed to overcome the barriers of cost-benefit analysis techniques, facilitating the inclusion of all possible

878 ABSTRACTS

combinations of decision-making parameters and their discrete values, which will eventually help the industry achieve cleaner seaborne transportation. To demonstrate the applicability of the proposed framework, this paper focuses on a real-life study case involving an environmental compliance problem in the Port of Copenhagen, Denmark, in relation to a particular EU Directive. In conclusion, the proposed framework can be applied as a generalised decision-making model to similar compliance issues encountered within other modes of transportation such as rail and road.

Air pollution Decision making Regulations Shipping

2015102363

Assessment of cost as a function of abatement options in maritime emission control areas. Transportation Research Part D: Transport and Environment, v 38 July 2015, pp 41-48 http://www.sciencedirect.com/science/article/pii/S1361920915000504 Lindstad, H., Sandaas, I., Strømman, A.H. English

This paper assesses cost as a function of abatement options in maritime emission control areas (ECA). The first regulation of air pollutions from ships which came into effect in the late 1990s was not strict and could easily be met. However the present requirement (2015) for reduction of Sulphur content for all vessels, in combination with the required reduction of nitrogen and carbon emissions for new-built vessels, is an economic and technical challenge for the shipping industry. Additional complexity is added by the fact that the strictest nitrogen regulations are applicable only for new-built vessels from 2016 onwards which shall enter US or Canadian waters. This study indicates that there is no single answer to what is the best abatement option, but rather that the best option will be a function of engine size, annual fuel consumption in the ECA and the foreseen future fuel prices. However a low oil price, favours the

options with the lowest capex, i.e. Marine Gas Oil (MGO) or Light Fuel Oil (LFO), while a high oil price makes the solutions which requires higher capex (investments) more attractive.

Compliance costs Emissions Regulations Shipping

2015102364

Research and analysis container shipping line on the basis of simulation. Naše More, v 62 n 2, June 2015, p 59 [8 p, 11 ref, 1 tab, 9 fig] http://hrcak.srce.hr/index.php?show=clanak&id_clanak_jezik=206793 Fetisov, V.A., Maiorov, N.N. English

Container transport is the main and leading form of transportation in shipping. Selection of the route for each voyage is determined by the nature of the traffic and operating conditions of the fleet. The best way to avoid any inconvenience when solving the predictive task of the liner ships is to use simulation taking into account both deterministic and stochastic processes arising from the operation of liner ships. The article describes a simulation model of a sea container line working on a regular container line in St. Petersburg (Russia), using mathematical model and proposed model “follow the leader” to describe the movement of ships. The main task in the simulation is to achieve an optimal balance between ship traffic and the decision on group forecast issues with the composition of the ships on the line.

Containerised shipping Mathematical models Scheduling Simulation

ABSTRACTS 879

2015102365

Assessment of the feasibility of the Arctic Sea transportation by using ship ice transit simulation. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4556-1. Volume 10: Polar and Arctic Science and Technology. Paper No. OMAE2014-24188 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912294 Valkonen, J., Riska, K. English

Arctic sea transportation has drawn a lot of attention in the recent years. The possibility of using a shorter route between Europe and Asia interests many in the shipping industry. Benefits from the shorter route may, at first, seem attractive. However, there might be factors affecting the feasibility of the route that are not obvious at first. The estimated transit speed along the Arctic route is not necessarily reached due to ice and other prevailing conditions. Simplified methods can underestimate the actual transit time, so the use of advanced methods is advisable. A thorough assessment of ship performance along the selected route can reveal factors that affect the feasibility of trans-Arctic shipping. This paper presents how the ship transit along an Arctic route can be simulated and how the ship performance can be assessed based on the simulation results. In this paper comparative results of ship performance in different ice conditions are shown and the benefits and challenges of the ship ice transit simulations are discussed. The effect of the input ice conditions to the ship performance estimates and how the ice information from various sources can be used for the simulations are discussed. Ship performance in the Arctic transit is tested using a probabilistic model called COSSARC for ship performance simulation in ice and open water. The tool can be used for assessing the economic feasibility of ship designs and transport concepts. One of the main benefits of the ship ice transit simulations compared to the simpler methods is that ice ridges are described in the realization of ice conditions statistically and the ship performance in ridges is modelled. A ship might get stuck in ridges and might be forced to wait for assistance from an icebreaker, or a double acting ship might travel slower than anticipated through ridge fields. This increases the transit time significantly, which is not necessarily revealed by simpler methods. The main outcome from the ship ice transit simulations described in this paper is a more realistic estimate of transit time for a given route. This can be used as input for economic or other assessments. It is possible to estimate the

probability of getting stuck in ice ridges from the ship ice transit simulation results, and thus the need for icebreaker assistance can be assessed. The probabilistic simulation of ship performance can be done in the design phase of the ship to assess various design concepts or while selecting what kind of ship or fleet of ships is the most suitable for the given transport task.

Arctic transportation Feasibility Ice transiting vessels Ship performance Simulation

2015102366

Goal setting of EEOI for chemical tankers by Monte Carlo simulation. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [7 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=4be4bfb7-ee6b-4f48-a2be-9938fe9085c1 Kurt, I., Boulougouris, E., Turan, O. English

In accordance with the current regulations, the companies have to investigate the suitability of the applied operational measures; to assess the available solutions for the energy efficiency improvement of their fleet; and produce more suitable operational measures or revise their already applied measures. For this purpose, there is need to have a SEEMP and achieve EEOI targets. In this paper, a method for the prediction of the annual performance of the energy efficiency for a company’s fleet, based on Monte Carlo Simulation is presented. As a case study, the method is applied on a chemical tanker fleet. Recorded voyage data, including EEOI values, cargo type and quantity, mileage covered, speed profiles, fuel types etc., will be used. Conclusions on the feasibility, usability, reliability as well as suggestions for further development of the method are included.

Chemical tankers Fuel consumption Monte Carlo method Ship performance

880 ABSTRACTS

2015102367

On two speed optimisation problems for ships that sail in and out of emission control areas. Transportation Research Part D: Transport and Environment, v 39 August 2015, pp 56-64 http://www.sciencedirect.com/science/article/pii/S1361920915000802 Fagerholt, K., Psaraftis, H.N. English

This paper deals with two speed optimisation problems for ships that sail in and out of Emission Control Areas (ECAs) with strict limits on sulphur emissions. For ships crossing in and out of ECAs, such as deep-sea vessels, one of the common options for complying with these limits is to burn heavy fuel oil (HFO) outside the ECA and switch to low-sulphur fuel such as marine gas oil (MGO) inside the ECA. As the prices of these two fuels are generally very different, so may be the speeds that the ship will sail at outside and inside the ECA. The first optimisation problem examined by the paper considers an extension of the model of Ronen (1982) in which ship speeds both inside and outside the ECA are optimised. The second problem is called the ECA refraction problem, due to its conceptual similarity with the refraction problem when light travels across two different media, and also involves optimising the point at which the ship crosses the ECA boundary. In both cases the objective of the problem is to maximize daily profit. In addition to mathematical formulations, examples and sensitivity analyses are presented for both problems.

Emissions Environmental protection Optimisation Ship speed

3.1 GENERAL HYDRODYNAMICS, HYDRAULICS AND OCEANOGRAPHY

2015102368

Smoothed Particle Hydrodynamics (SPH) method for modelling 2-dimensional free surface hydrodynamics. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 6 [8 p, 17 ref, 11 fig] https://www.crcpress.com/product/isbn/9781138027893 Ramli, M.Z., Temarel, P., Tan, M. English

The main goal of the current research is to implement Smoothed Particle Hydrodynamics (SPH) for the prediction of wave-induced motions and loads within the framework of 3D modelling. In this paper, the focus is twofold. First, implementation of possible additional terms to the standard Incompressible SPH (ISPH) method with reference to generating/propagating regular waves in 2D domain, using a piston wave maker. Improvements to the prediction of pressure and velocity fields are then carried out with kernel renormalization technique and shifting technique without increasing the computational cost. The arc method is employed to improve the accuracy of free surface recognition, i.e. “noise-free” free surface. In addition, the Weakly Compressible (WCSPH) is also applied to the problem of 2D regular wave generation. Comparisons of predicted free surfaces, their kinematic and dynamic characteristics between ISPH, WCSPH and analytical solutions for a range of frequencies are carried out. The second focus of the paper is the 2D radiation problem due to forced sinusoidal oscillation of a rectangular section floating on calm water. The predicted hydrodynamic actions and coefficients in sway by WCSPH are then compared against available experimental measurements.

Free surfaces Hydrodynamics Numerical models Wave propagation

ABSTRACTS 881

2015102369

Application of focusing wave groups in model testing practice. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23949 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912085 Schmittner, C., Brouwer, J., Hennig, J. English

For hydrodynamic model testing different types of model waves are applied, where the most common ones are regular (monochromatic) and irregular (multichromatic) waves. In addition to these wave types the application of focusing wave groups, which are also often denoted as wave packages or transient wave packets, can give insight into aspects that cannot be assessed by the conventional model waves. This paper describes the different applications of focusing wave groups for hydrodynamic model testing. The paper starts with the historical background, followed by a theoretical description and the generation procedure. The main part of the paper is dedicated to the practical application of focusing wave groups in the basin. Items that are described are a) the derivation of transfer functions for floating structures and for anti-roll tanks b) the determination of hydraulic and electrical transfer function of wave makers c) the verification of position and calibration of wave probes in the basin d) the generation of extreme wave events e) the assessment of reflection coefficient of beaches f) the investigation of non-linear aspects of transfer functions. Finally, characteristics of the analysis of focusing waves are introduced and compared to conventional methods based on regular and irregular waves.

Model tests Wave groups

2015102370

Application of fuzzy time series techniques in wind and wave data forecasting. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24612 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911698 Stefanakos, C.N., Schinas, O., Eidnes, G. English

This work explores the applicability of widely known fuzzy time series forecasting techniques for the prediction of wind and wave data. These techniques have extensively been used with great success to the forecasting of stock prices. In the present work, long-term time series of wind speed, significant wave height, and peak period are examined and used for the verification of the forecasting performance of the fuzzy models. To examine the forecasting accuracy, the root mean squared error (RMSE) is used as an evaluation criterion to compare the forecasting performance of the listing models. As the importance of quality of wind and wave data increases, effective forecasting could further benefit designers of offshore structures and environmental researchers.

Forecasting Time series analysis Wave data Wind

3.2 RESISTANCE AND PROPULSIVE PERFORMANCE

2015102371

Re-analysis of William Froude’s studies of planing craft. RINA Transactions - International Journal of Small Craft Technology, v 157 Part B1, January-June 2015 http://www.rina.org.uk/ijsct.html Morabito, M.G. English

One of William Froude’s lesser-known contributions to the field of Naval Architecture was in conducting some of the earliest studies on planing craft. Froude’s research was prompted by the idea of an inventor, Reverend C.M. Ramus who in 1872 proposed a high-speed ship concept using a flat-bottomed, stepped planing hull. Ramus later

882 ABSTRACTS

suggested the use of this hull form for rocket-propelled rams. Froude conducted towing tests on a model of the Ramus hull, as well as on a model three-point hydroplane concept of his own design. He also derived a solution for the optimum trim angle and minimum resistance of planing craft, using his recently developed formulae for estimating frictional resistance on flat plates and lift forces on submerged plates. Froude’s study demonstrated that Ramus’s ideas were not feasible at the time and the study received very little attention. It was not until the advent of lightweight internal combustion engines, thirty years later, that planing hulls became a reality. In this paper, the Ramus tests are re-analysed and the data are put into a modern format. Comparisons are provided between the Ramus hull, Series 62 and a planing flat plate. The Ramus concept is shown to have had significantly more drag than would be expected from a planing hull. New model tests explore the effects of the rounded stern of the Ramus hull, and show that this feature significantly increases the resistance. Froude’s derivation of the minimum resistance of planing craft is discussed and contrasted with modern methods for prismatic planing hull resistance prediction.

Hull resistance Planing hulls

2015102372

Comparative numerical analysis of the flow pattern and performance of a foil in flapping and undulating oscillations. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 257-277 http://link.springer.com/article/10.1007/s00773-014-0297-7 Abbaspour, M., Ebrahimi, M. English

Nature presents a variety of propulsion, maneuvering, and stabilization mechanisms which can be inspired to design and construction of manmade vehicles and the devices involved in them, such as stabilizers or control surfaces. This study aims to elucidate and compare the propulsive vortical signature and performance of a foil in two important natural mechanisms: flapping and undulation. Navier–Stokes equations are solved in an ALE framework domain containing a 2D NACA 0012 foil moving with prescribed kinematics. All simulations are carried out using a pressure-based finite volume method solver. The results of time-averaged inline force versus Strouhal number (St) show that in a given Reynolds number (Re), the flapping oscillations begin to

produce thrust at a smaller St, and with a greater slope than undulatory oscillations. However, consumed power of the flapping foil versus St varies with considerably higher values and greater slope than undulating foil. In addition, efficiency graphs show similar ascending–descending behaviors versus St, with greater “peak propulsive efficiency” for the undulating foil. Furthermore, one of the most important differences between the vortical structures of flapping and undulatory oscillations is the distinguishable appearance of leading edge vortices in the wake of the flapping foil without observable ones in the wake of undulating foil. Finally, the formation and dissipation patterns of distinct vortices in the wakes of both oscillating foils vary with St.

Foils Oscillations Propulsive efficiency

2015102373

Numerical analysis of the interference effects on resistance, sinkage and trim of a fast catamaran. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 292-308 http://link.springer.com/article/10.1007/s00773-014-0283-0 He, W., Castiglione, T., Et al English

The purpose of this paper is the numerical investigation of the interference phenomena between the waves generated by the individual hulls of a catamaran. The study focuses on the effects of both Froude number and demi-hull separation distance on resistance and on sinkage and trim. The numerical simulations are carried out by the URANS solver CFDShip-Iowa V.4 and, to assess the capability for prediction of resistance, sinkage and trim of the URANS code for twin-hull configuration vessels, a verification and validation study is performed for global as well as for local variables. A very good agreement between the numerical results and the experimental data is obtained, and the validation study demonstrates the high level of accuracy of the current predictions, which are used to have a better insight into the interference phenomena. In accordance with the experiments, within Fr = 0.45–0.65, the catamaran has a significantly higher resistance coefficient compared to the mono-hull; furthermore, the C T value increases with decreasing the separation distance between the twin hulls. On the contrary, at Fr lower than 0.45 and at Fr higher than 0.65, the effects of hull spacing on resistance as well as on sinkage and trim can be neglected. The flow

ABSTRACTS 883

field characteristics, wave pattern, wave cuts and pressure distributions are analysed through the CFD analysis. Finally, the effects of the Reynolds number on resistance are also investigated and results show a small decrease in interference with increasing the Reynolds number.

Catamarans Numerical analysis Resistance Sinkage Trim

2015102374

On the scale effect of thrust deduction in a judicious self-propulsion procedure for a moderate-speed containership. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 373-391 http://link.springer.com/article/10.1007/s00773-014-0289-7 Lin, T-Y., Kouh, J-S. English

The authors studied the scale effect of the thrust deduction factor on an innovative self-propulsion procedure. In contrast to the International Towing Tank Conference (ITTC) committee documents, which adopt a skin friction corrector and also state that the thrust deduction factor is the same for both the model and full scales, complex interaction remains unresolved. Since the skin friction corrector is always calculated by an equation, to date no verifications of this equation have been published. In addition, the scale effect of the thrust deduction factor has seldom been studied because it is minor compared to that of the wake fraction. In the first section of this paper, the existence of the scale effect on the thrust deduction factor is proven and the misinterpretation of the equality is highlighted. Second, a balanced self-propulsion procedure, which does not use the skin friction corrector to isolate the propeller loading effect is proposed and compared to the conventional standard ITTC procedure. The study derived a simplified model for predicting the full-scale values for the thrust deduction factor correction. The new procedure was applied to a moderate-speed

containership by CFD software and several characteristics were demonstrated. The scale correction model was verified from the computational results.

Computational fluid dynamics Containerships Scale effect Self propulsion Thrust deduction

2015102375

Vibration control by propeller design. A Yücel Odabaşi Colloquium Series, 1st International Meeting – Propeller Noise & Vibration; 6-7 November 2014; Istanbul, Turkey. Organised by Istanbul Technical University Faculty of Naval Architecture and Ocean Engineering. P 1 [6 p, 6 ref, 3 tab, 10 fig] http://www.ayocol.itu.edu.tr/files/AYOCOL_2014_Proceedings.pdf Bodger, L., Helma, S., Sasaki, N. English

Propeller research has generally been focussed on improving the open water efficiency, and by considering the various energy losses associated with the marine screw propeller, it can be seen that for a design brief with given main engine power and RPM input, plus a thrust requirement defined by the specified ship speed, the most fruitful area for improvement in efficiency by propeller design is a reduction in energy losses. The simple way to increase the efficiency is reduction of blade area, increase a load near the tip and larger diameter with low RPM. However, the vibration and noise will be the first obstacle thing when a designer tries to increase the efficiency of the propeller by these ways. This paper presents the simple prediction method of pressure fluctuations induced by thickness, propeller loading and unsteady cavitation taking not only propeller dimensions but also stern shape in the beginning of propeller design stage.

Energy dissipation Propeller cavitation Propeller efficiency Propeller loading Propeller vibration

884 ABSTRACTS

2015102376

A scaling procedure for modern propeller designs. A Yücel Odabaşi Colloquium Series, 1st International Meeting – Propeller Noise & Vibration; 6-7 November 2014; Istanbul, Turkey. Organised by Istanbul Technical University Faculty of Naval Architecture and Ocean Engineering. P 7 [11 p, 10 ref, 1 tab, 10 fig] http://www.ayocol.itu.edu.tr/files/AYOCOL_2014_Proceedings.pdf Helma, S. English

The extrapolation procedures currently used to scale propeller characteristics tested at model scale to their full scale performances are either based on a statistical, the Lerbs-Meyne or the recently developed strip method. With the emergence of so-called unconventional propellers and different design strategies associated with them, it has been questioned whether the assumptions used in these scaling methods are still universally valid. e.g. with tip and root unloading employed the circulation distribution deviates from the optimum, which is assumed by the Lerbs-Meyne method; more modern profiles show a different camber distribution and hence the drag coefficient must be aligned with the hydrodynamic inflow angle and not with the pitch to diameter ratio as assumed by the strip method (and implicitly by the ITTC 1978 method). The work presented still uses the assumption of the equivalent profile and explains three possible modified scaling procedures ultimately resulting in a way to calculate the hydrodynamic inflow angle solely from one open-water test conducted at a constant Reynolds number. Finally exemplary results comparing a propeller of conventional type with a recent propeller design is also shown. The new proposed method shows a superior performance when compared to other scaling methods.

Propeller efficiency Propeller models Scale effect

2015102377

Experimental determination of the difference in visual and acoustic cavitation inception. A Yücel Odabaşi Colloquium Series, 1st International Meeting – Propeller Noise & Vibration; 6-7 November 2014; Istanbul, Turkey. Organised by Istanbul Technical University Faculty of Naval Architecture and Ocean Engineering. P 19 [5 p, 4 ref, 1 tab, 8 fig] http://www.ayocol.itu.edu.tr/files/AYOCOL_2014_Proceedings.pdf Johannsen, C., Zarbock, O., Bretschneider, H. English

For naval ships, research or passenger vessels as well as high comfort class mega yachts the noise generating effect of propeller cavitation can be a problem. The ship speed up to which the propeller operates free of cavitation is a quality feature here. Cavitation inception tests with complete ship models carried out in large testing facilities are a standard to predict cavitation inception for those ships. Purely visual cavitation investigations, however, suffer from the fact that cavitation might be hearable already before it can be detected by eye. On the other hand, scaling effects involved in vortex cavitation inception can spoil the result of a purely acoustic inception test at model scale. To overcome these problems an experimental study was performed to determine the gap between acoustic and visual tip vortex cavitation inception for a full scale propeller blade tip of 1.8 m characteristic chord length. In a large range of Reynolds numbers up to almost full scale values and at different angles of attack acoustic and visual cavitation inception points were determined separately. As a result it can be stated that the difference between visual and acoustic propeller cavitation inception speed is much smaller than two knots as commonly assumed.

Cavitation inception Cavitation tests Scale effect Tip vortices

ABSTRACTS 885

2015102378

Systematic cavitation tunnel tests of a propeller in uniform and inclined flow conditions as part of a round robin test campaign. A Yücel Odabaşi Colloquium Series, 1st International Meeting – Propeller Noise & Vibration; 6-7 November 2014; Istanbul, Turkey. Organised by Istanbul Technical University Faculty of Naval Architecture and Ocean Engineering. P 25 [12 p, 25 ref, 5 tab, 20 fig] http://www.ayocol.itu.edu.tr/files/AYOCOL_2014_Proceedings.pdf Aktas, B., Turkmen, S., Et al English

This paper presents a systematic cavitation tunnel tests with a 214mm diameter model propeller of a catamaran research vessel, which is subjected to uniform and inclined flow conditions, to investigate its efficiency, cavitation and underwater radiated noise characteristics. The experiments were conducted in the Emerson Cavitation Tunnel of Newcastle University based on the starboard side of the 5-blades and right-handed propeller of the University’s research vessel, The Princess Royal. In the paper the details of the tests and results of the significant findings for the effect of the shaft inclination on the propeller efficiency, cavitation and underwater radiated noise characteristics are discussed. A better understanding is sought in relation to the noise signatures of different types of cavitation. The systematic tests presented in the paper also have a long term objective, which will be achieved in due course, as being the first experiment of an organized round robin test campaign that is being currently undertaken by the 7 members of the Underwater Noise Community of Practice (CoP) of Hydro-Testing Forum (HTF) for which the University of Newcastle is a member. This long term objective is to repeat similar tests in the different facilities of all CoP members to reveal the relative merits of their testing facilities for underwater noise investigations, hence to learn more from their practices and experiences.

Cavitation tests Propeller cavitation Propeller noise

2015102379

Propeller acoustic measurements in atmospheric towing tank. A Yücel Odabaşi Colloquium Series, 1st International Meeting – Propeller Noise & Vibration; 6-7 November 2014; Istanbul, Turkey. Organised by Istanbul Technical University Faculty of Naval Architecture and Ocean Engineering. P 37 [10 p, 13 ref, 2 tab, 31 fig] http://www.ayocol.itu.edu.tr/files/AYOCOL_2014_Proceedings.pdf Haimov, H., Gallego, V., Et al English

The study describes the implementation of experimental procedure for measuring the hydrodynamic noise generated by model scale marine propellers in atmospheric towing tank. The towing carriage and conditions have not been altered admitting the existence of considerable background noise. The feasibility analysis included experimental and theoretical study of the background noise at the operating conditions. Some considerations about the uncertainty of the results are also presented. The experimental equipment, set up and procedure for measuring the acoustic pressure around model ship propeller and/or hull is also described. Simultaneous measurements with various differently positioned hydrophones at multiple hydrodynamic conditions permitted to evaluate the background and propeller/hull generated acoustic field at a range of frequencies. An appropriate treatment of the recorded time series characterised the background disturbances and permitted to obtain net results with sufficient signal to noise ratio, mostly from narrowband spectral analysis. Results for the impact of the hull presence on propeller acoustic field are presented and discussed. The extrapolated results are compared informatively with full scale measurements.

Acoustics Model tests Propeller noise

886 ABSTRACTS

2015102380

Numerical and experimental research on a podded propulsor. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24015 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912093 Islam, M., Ryan, R., Molynuex, D. English

This paper presents methodologies and some results of a numerical and experimental program to evaluate the effects of static azimuthing conditions on the propulsive characteristics of a puller podded propulsor in open water. In the experimental effort, the model propulsor was instrumented to measure thrust, torque and rotational speed of the propeller, and three orthogonal forces and moments, and azimuthing angle of the pod. The experimental results included the bare propeller (ahead only) and the combined propeller and pod over a range of advance coefficients at various static azimuthing angles in the range of −180° to 180°. A complementary numerical study is being carried out to predict the hydrodynamic forces of podded propulsor in static azimuthing conditions. A Reynolds-Averaged Navier Stokes solver is used to predict the propulsive performance of the bare propeller as well as the podded propulsor system. The thrust and torque for the bare propeller were compared to the corresponding measurements. The propeller thrust and torque as well as the loads on the pod in straight-ahead condition and at static azimuthing angles were then compared with the measurements. Preliminary analysis demonstrates that the RANS solver could predict the performance coefficients of the bare propeller as well as the podded propulsor in straight-ahead and static azimuthing angles in puller configurations.

Electric drives Model tests Numerical analysis Pods Propulsive performance

2015102381

Design and analysis of trochoidal propulsors using nonlinear programming optimisation techniques. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24093 [15 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912104 Roesler, B.T., Francisquez, M., Epps, B.P. English

Flapping foil propulsors may increase the propulsive efficiency of large shipping vessels. This paper presents the design of a notional propulsor for an inland waterway vessel. Calculations for the trochoidal propulsor are performed using a lumped, two-dimensional model, which includes the influence of the free vortex wake, as well as approximations to account for three-dimensional effects. The numerical model is used to optimise the foil pitch function in order to achieve the highest efficiency for given geometric and operational parameters. Foil-to-foil interactions are studied for multiple-foil propulsors to determine effects of blade number on hydrodynamic efficiency. Considerations of packaging options for a trochoidal propulsor are explored. The results presented herein can also be applied to large- and mid-sized ships, such as international shipping vessels, fishing vessels, cruise liners, and military ships.

Design Foil propellers Optimisation Propulsive efficiency

2015102382

Hydrodynamic performance of an S-SWATH ship in calm water and waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24100 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912105 Qian, P., Yi, H., Li, Y. English

An unconventional SWATH (Small-Waterplane-Area-Twin-Hull) ship is introduced, named S-

ABSTRACTS 887

SWATH, which is a catamaran with twin hulls that are slightly curved in an S-form and arranged at a mean yaw angle but mirror symmetric to their common longitudinal centre plane. Based on the “shallow-channel superconductivity” theory, proposed by Chen and Sharma, in this paper a more accurate viscous flow theory, solving the Reynolds-averaged Navier–Stokes equations (or RANS equations), is used to study the hydrodynamic performance of the S-SWATH ship. The simulation results of calm-water resistance and motions in waves are presented. In comparison with a benchmark conventional SWATH ship, which features a typical torpedo-shaped body, the simulation results prove the effectiveness of the S-shape design. On one hand, the S-SWATH ship inherits the major advantages of SWATH ships, such as the superior ride quality, acceptable acceleration levels for human habitability and therefore comfort and overall superior seakeeping characteristics. On the other hand, the S-SWATH ship has much less low-speed drag than its conventional SWATH counterpart, and comparable total drag at high speeds.

Catamarans Resistance Seakeeping SWATH ships

2015102383

Cavitation of a propeller and influence of a wake equalizing duct. TransNav, v 9 n 2, June 2015, p 235 [7 p, 9 ref, 12 fig] http://www.transnav.eu/Article_Cavitation_of_a_Propeller_Martinas,34,578.html Martinas, G. English

The wake equalizing duct (WED) is one of the most commonly used energy saving devices for improving the propulsion performance of a ship; and reducing the propeller-excited vibrations and viscous resistance forces. During the last three decades considerable research and development activities have taken into place within this context. Most of these devices are used to improve propulsive efficiency, but some of them aim to improve other performance characteristics, such as cavitation, vibration, noise, manoeuvrability, etc. Marine propellers are the most common propulsion systems; nevertheless, it is possible to improve its propulsive performance using additional auxiliary propulsor devices (unconventional propulsors). Two versions of an existing ship in normal version and fitted with WED

device were analysed in order to demonstrate the influence on the WED device on the propeller cavitation. It was determined that the values for the pressure coefficient are 1.98 for without WED situation and 2.029 for WED situation. The difference is not so significant that, the conclusion is that the WED device didn’t have influence over the propeller cavitation. Either optimisation of dimensions and form of the WED didn’t help in reducing the negative effects of cavitation.

Ducted propellers Propeller cavitation

2015102384

Research on integrated optimal design method of propeller and PBCF (Propeller Boss Cap Fins). Shipbuilding of China, v 55 n 3, 2014, pp 101-107 http://oversea.cnki.net/kcms/detail/detail.aspx?filename=ZGZC201403011&DBName=cjfqtotal&dbcode=cjfq Cai, H., Chen, K., Et al Chinese

In this article, PBCF and propeller are considered as a whole unit and an integrative design procedure is carried out, in which uploading at blade root is emphasized. Uploading in blade root will generate hub vortex, which can be restrained by PBCF because of its energy saving mechanism. An integrative propeller-PBCF design method is provided. Potential flow theory, CFD tools, artificial intelligence optimisation algorithm, and model tests are applied in completion of this design method. Model test data indicate higher efficiency of the propeller-PBCF unit by this design method, and utility, robustness and practicality of the design method is shown.

Design Propeller efficiency Propeller hubs

888 ABSTRACTS

3.3 MOTION, SEAKEEPING AND MANOEUVRING

2015102385

Experimental investigation of the influence of hull damage on ship responses in waves. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 1 [8 p, 22 ref, 4 tab, 14 fig] https://www.crcpress.com/product/isbn/9781138027893 Bennett, S.S., Phillips, A.B. English

A number of high profile ship damage events in recent years have highlighted ship safety concerns following such an incident. With damage incidents occurring with relatively high frequency, the survivability of damaged ships needs to be better understood and modelled. Damage may result in: water in-flux, free surface effects, and abnormal load distributions, these will influence ship stability, motions and global loading. This paper experimentally investigates the influence of abnormal loading on the motions and vertical bending moments experienced by a 1:44 scale Leander Class frigate operating in regular waves for in-tact, one and two compartment damage. Results show that the inclusion of an abnormal mass distribution due to damage has a significant effect on the magnitude of the motion and response RAOs in head and beam seas; the severity of this effect increases with forward speed.

Hull damage Model tests Ship response

2015102386

Comparison of two practical methods for seakeeping assessment of damaged ships. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 5 [8 p, 9 ref, 3 tab, 10 fig] https://www.crcpress.com/product/isbn/9781138027893 Parunov, J., Ćorak, M., Gledić, I. English

The purpose of the paper is to compare two simplified methods that may be used for modelling wave-induced motion and resulting structural loads of ship damaged in collision or grounding accident. The first

method is the added mass method, in which it is assumed that the mass of the flooded seawater becomes integral part of the ship mass and moves with the ship. The second approach is the lost buoyancy method, where structure of damaged tanks and all of its contents are removed from the vessel. The former method is applicable for small damages while the latter is more suited for large damage extents. Response amplitude operators of vertical motions and hull girder vertical wave bending moments at amidships are calculated by the state-of-the-art linear 3D panel hydrodynamic code and compared to those for intact ship as the effect of damage is often neglected in computation of motions and wave loads of damaged vessel. An attempt of verification of procedures is done by comparison with seakeeping experiments on damaged warship, described in available literature.

Damage Seakeeping Ship motions Wave loads on ships

2015102387

Unstructured MEL scheme for 3D body nonlinear ship hydrodynamics. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 2 [8 p, 12 ref, 2 tab, 9 fig] https://www.crcpress.com/product/isbn/9781138027893 Chapchap, A.C., Temarel, P. English

The radiation forces for a body oscillating on the free surface are investigated through a solution in the time domain accounting for the changes in the submerged geometry of the body. The solution is obtained in the context of a Mixed Eulerian-Lagrangian (MEL) scheme using direct Boundary Element Method (BEM). An important issue when the body submerged geometry changes concerns the accurate evaluation of the velocity potential time derivative. In this work, two approaches are proposed to tackle this problem. Results are presented for a sphere and a Wigley hull undergoing forced oscillations in the heave mode with large amplitudes of motion. The predictions of the heave related hydrodynamic forces and coefficients are compared against available

ABSTRACTS 889

experimental measurements and other numerical methods. Sensitivity studies investigating the influences of mesh density, domain size, damping beach size and amplitude of forced motion are also discussed.

Heaving Numerical analysis Ship hydrodynamics Wigley models

2015102388

An initial estimation of DP requirements for a non-moored operational FPSO. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 3 [8 p, 15 ref, 1 tab, 7 fig] https://www.crcpress.com/product/isbn/9781138027893 Hearn, G.E., Bratu, G.C. English

This paper presents a direct estimate of the dynamic horizontal plan positioning forces and moment to keep a proposed Floating, Production and Storage Offloading system (FPSO) with open moonpool on station, without moorings, through novel application of standard frequency domain motion response analysis. Reasons for selecting frequency domain over time domain formulations presented is justified. Quality of hydrodynamic reactive quantities, required in motion response formulation, from a third party 3D boundary element based formulation is discussed in terms of expected cross term symmetry, with warning of how blind software application can be erroneous. Combining motions from standard unconstrained motion equations and global thruster loading requirements from a novel response formulation, the time-averaged DP thruster cluster power is estimated. Hence individual thruster power can be assigned recognizing the redundancy requirements of a Class 3 DP system.

Dynamic positioning FPSOs

2015102389

Numerical simulation of the dynamics of a large moored tanker. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 8 [9 p, 8 ref, 10 tab, 12 fig] https://www.crcpress.com/product/isbn/9781138027893 Zhang, S., Jin, Q., Et al English

In this paper, the dynamics of a large moored tanker, in wind, waves and current, is investigated using the commercial software AQWA. Two typical mooring types are implemented, namely I-type and V-type, to examine the motion response of the moored tanker and the relevant cable tension under different environmental conditions. The results show that the V-type configuration reduces surge, sway and cable tension. The offloading system, with the tanker in tandem behind the FPSO, is further investigated using the V-type mooring configuration and comparing it to the conventional offloading system, in which the tanker is attached to the FPSO only with a hawser. The investigations show that the V-type configuration has advantages in terms of motion response and cable tension over the hawser connection.

Moored vessels Numerical models Ship motions

2015102390

Trajectory tracking of underactuated surface vessels based on neural network and hierarchical sliding mode. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 322-330 http://link.springer.com/article/10.1007/s00773-014-0285-y Liu, C., Zou, Z., Yin, J. English

Adaptive robust controllers are proposed for trajectory tracking and stabilization of underactuated surface vessels simultaneously in this paper. Hierarchical sliding mode is employed to deal with the underactuation of the model, and neural network is used as a tool for approximating unknown nonlinear function in the system; in this way, the robustness of the proposed controller is strengthened, and the chattering problem of sliding mode technique is relieved. The nonlinear damping terms of ship’s model are considered which are neglected in many

890 ABSTRACTS

studies, and the time-varying disturbances are taken into account to test the robustness of the designed controllers. Stability is guaranteed by Lyapunov theorem, and the proof is given. Numerical simulations are implemented to demonstrate the effectiveness and the robustness of the designed controllers.

Controllers Neural networks Tracking Vessels

2015102391

Second-order low-frequency drift motions of a floating body calculated by different approximation methods. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 357-372 http://link.springer.com/article/10.1007/s00773-014-0288-8 Pessoa, J., Fonseca, N. English

The paper presents an experimental and numerical investigation of the low-frequency motions of a simple geometry floater subjected to bichromatic waves and to long crested irregular seas. The body is axis-symmetric about the vertical axis and it is restrained from drifting away by a linear mooring system. The investigation is carried out for three water depths representing deep water, intermediate water depth and shallow water. The objective is to assess the water depth influence on the second-order low-frequency motions. A second objective is to assess the results of different approximations for the second-order difference frequency wave exciting forces on the second-order motions. The quadratic transfer functions are calculated with a boundary element method using several levels of approximation for the second-order forces: (a) the most complete approximation solves the boundary value problem completely up to the second order, (b) the first-order approximation neglects the free surface forcing in the 2nd order boundary value problem solution, (c) Newman’s approximation is of zeroth-order with respect to the difference frequency, (d) a fourth method combines Newman’s approximation with a contribution from the second-order incident wave potential, (e) the fifth method is applied to the heave forces only and it combines Newman’s approximation corrected by an additional set down. This study shows that the contribution from the second-order velocity potential must be considered for shallow water calculations to achieve accurate

results. For small difference frequencies, second-order scattering potential effects are small; therefore, in this case, a good practical approximation consists on considering the second-order potential is contributed by the incident waves only.

Approximation Floating bodies Motion

2015102392

A study on vertical motions of high-speed planing boats with automatically controlled stern interceptors in calm water and head waves. Ships and Offshore Structures, v 10 n 3, June 2015, pp 335-348 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.867647#.VYfbLU3JCUk Karimi, M.H., Seif, M.S., Abbaspoor, M. English

The controllable flaps and interceptors in planing crafts not only may reduce the resistance, but also could be designed to make a boat run at or near optimum attitude in various environments, which results in a reduction in both resistance and vertical motion in waves. Planing vessels suffer from porpoising instability and violent vertical motion at high forward speeds. The controllable flaps and interceptors can be used to control and reduce the vertical motion of planing crafts. In the present study, the impact of controlled interceptors on a planing craft seakeeping quality is investigated through application of experimental and theoretical methods. In the experimental part of the study, a scaled-down model of a high-speed planing catamaran is tested with and without controllable stern interceptors in calm water and regular head waves, to investigate the effect of automatically controlled interceptors on vertical motion reduction of the model. Through application of modern optimal control theory and Savitsky's method, a control-oriented model of the vertical motion of the planing boat with interceptors in calm water and waves is developed. A simulation environment has been developed in MATLAB and SIMULINK. MATLAB has been used to formulate the model and to provide a suitable environment for control studies. The results obtained, the model, shows good agreement between the experimental and simulated data. Both the experimental and simulated results show that controllable aft interceptors can be used not only for minimising resistance, but also for reducing the vertical motions, especially at or near the resonant frequency. The results also proved that in automatic control system for controlling stern

ABSTRACTS 891

interceptors, a feedback of pitch angle and pitch velocity to the interceptors are effective for vertical motion damping of planing boat in calm water and head waves.

Control surfaces High speed vessels Planing hulls Seakeeping Ship motions

2015102393

Development of minimum bow height formula for Indonesian waters. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 1, p 1 [11 p, 11 ref, 9 tab, 12 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Zaky, M. English

Freeboard was considered long ago as an important element of ship safety. It was recognized that in order to maintain seaworthiness ships must possess some amount of reserve buoyancy, i.e. some volume above the water-plane and below the watertight deck. Indonesian Bureau Classification, known as BKI (Biro Klasifikasi Indonesia) has authorized by the Government to carry out the survey and certification of load line. The study of minimum freeboard and bow height will be performed on ships register BKI for Indonesian waters are later become a reference in the calculation on load line. Bow height correction is performed based on probability of deck wetness analysis using strip theory. Both analysis of ship response (RAO) are performed at two positions are amidships position by beam sea condition that affect rolling motion and stem position by head sea condition that affect coupled motion of heaving and pitching. Probability of deck wetness was taken from the stern, amidships and particularly on stem position for 22 ship models. Development of the bow height calculation was modified using 4 scenarios that resulted linear regression formula of bow height minimum by ships length and wave height as parameters where the optimum results are in scenario 3 which assumes when the longer of the ships makes the wave higher and these results allow to reduce of

bow height minimum up to 35 % from bow height minimum calculation according to Regulation 39 ILLC 1966 as amended Protocol 88.

Bows Deck wetness Freeboard Height Seakeeping

2015102394

What is surf-riding in irregular seas? ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 1, p 12 [7 p, 4 ref, 3 tab, 7 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Spyrou, K.J., Themelis, N., Kontolefas, L. English

The concept of surf-riding in irregular seas discussed and two calculation schemes are implemented in order to create upper and lower bounds of the probability of surf-riding. The first scheme is focused on the identification of the generation and disappearance of surge equilibria. Due to the time-varying nature of the dynamical system, these are finite-time objects, departing from the conventional notion of an equilibrium. The other scheme is aimed to determine time segments of ship motion where the mean speed is higher than expected. The probability values obtained by the two schemes are compared against each other and conclusions are drawn.

Irregular waves Mathematical models Ship motions

2015102395

Quantitative assessment of ship behaviour in critical stern quartering seas. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 1, p 19 [9 p, 22 ref, 2 tab, 9 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Acanfora, M., Matusiak, J. English

Following and stern quartering seas, combined with a

892 ABSTRACTS

relatively high speed of vessel, represent the operational conditions which may lead the ship to dangerous situations in adverse weather. Recently, IMO efforts were addressed to the development of the Second Generation Stability Criteria, based on three different safety levels. The third level requires a direct assessment of ship stability, based mainly on numerical simulation of ship motions in waves. The numerical simulation tool is expected to reproduce vessel dynamics, in order to allow detailed design analysis when assessing ship safety. This paper presents an application of the numerical model called LaiDyn to the investigation of ship large amplitude motions, in critical conditions typical for a conventional RoPax vessel. LaiDyn is a six-degree of freedom dynamic model, in time domain, that works on a discrete representation of the hull, using panels. The non-linear restoring generalized forces and the Froude-Krylov wave loads are evaluated, at each time, on the instantaneous ship wetted surface. Radiation and diffraction forces are derived using linear model. The ship resistance and the propeller thrust are also implemented into LaiDyn. For the purpose of the numerical applications, stern quartering irregular sea is assumed.

Numerical models Quartering seas Rolling Stability

2015102396

Regulatory use of nonlinear dynamics: an overview. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 1, p 28 [8 p, 8 ref, 4 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Peters, W.S., Belenky, V., Spyrou, K. English

The paper is focused on the physical background of the second level vulnerability criterion for surf-riding /broaching-to as a part of the second generation IMO intact stability criteria. The criterion is based on nonlinear dynamics, homoclinic bifurcation, in particular, and uses the Melnikov method for calculations. While, well understood in the scientific community, these concepts may present a challenge for regulatory use as most practicing naval architects are not familiar with these concepts. The paper presents an explanation of the criterion background

using conventional Naval Architecture physical concepts, and gives an overview of the dynamical aspects of the calculation procedure.

Broaching Mathematical models Ship motions Stability Surging

2015102397

Applicability of the difference between population statistics as an acceptance criteria metric for seakeeping validation. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 1, p 36 [8 p, 7 ref, 7 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Zuzick, A.V., Reed, A.M., Et al English

The difference between population statistics is proposed as a primary acceptance criteria metric for the direct quantitative validation of ship simulation tools in support of accreditation for uses related to ship motions in irregular seas. The discussion is applicable to comparisons of statistical quantities calculated from ship motion time histories generated by simulations and benchmark data such as scale-model test results. The difference between population statistics provides several of the key characteristics desirable in acceptance criteria, including quantifiable measures of accuracy, completeness, and self-consistency. Further, this metric can be applied to a variety of statistical quantities of interest, provides an opportunity to extend parameter-level comparison results to a broader measure of overall accuracy, and allows for straightforward application of engineering margins traceable to simulation tool performance requirements. Use of the difference between values (often called the error) as the foundation of comparison metrics is not a new concept in the field of validation, but its use is not frequently associated with acceptance criteria for simulations of stochastic processes. Much work has been completed to characterize the total uncertainties from various sources associated with each data set in a comparison of this type. Extension of that body of work to the

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uncertainty associated with the comparison itself provides a robust measure of parameter accuracy and a flexible and adaptable acceptance criteria foundation.

Seakeeping Simulation Validation

2015102398

Remarks on experimental validation procedures for numerical intact stability assessment with latest examples. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 3, p 77 [7 p, 8 ref, 1 tab, 15 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Umeda, N., Kawaida, D., Et al English

For facilitating development of the guidelines of direct stability assessment as a part of the second generation intact stability criteria at the IMO (International Maritime Organization), this paper provides examples of comparison between model experiments and numerical simulations for stability under dead ship condition and for pure loss of stability in astern waves. As a result, some essential elements for reasonable validation were identified. For dead ship stability, adequate selection of representative wind velocity generated by wind fans is crucial. For pure loss of stability, accurate Fourier transformation and reverse transformation of incident irregular waves are important. These remarks should be reflected in the guidelines as appropriate.

Model tests Numerical models Stability Validation

2015102399

Model experiments in following and quartering seas using a small size ship model. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 3, p 85 [9 p, 4 ref, 1 tab, 14 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Nakamura, M., Yoshimura, Y., Shiken, D. English

When performing a free-running model test, a large scale ship model and basin are conventionally required because of the need to install a lot of driving and measuring apparatus. Generally there is a large cost for the model test. Therefore, it would be better and convenient if a small free-running ship model could be realized. The authors have been trying to develop small size driving and measuring apparatus for such a small size ship model, and trying to carry out free-running model tests in waves in a small basin. Although there are significant problems about weight and space for the onboard apparatus, the small size of servo driving unit of propulsion motor as well as steering gear have been developed. The electric power for these apparatus is supplied by only one small lithium-polymer battery. Meanwhile, for the measurement of ship trajectory and speed, a total station system is utilized. Using such a ship model, the authors have successfully measured the ship motion of surf-riding and broaching, and reveal the occurrence condition of these phenomena as an example. From these data, initial conditions of surf-riding and broaching also can be clarified even in such small ship model and towing basin.

Broaching Following seas Model tests Quartering seas Ship motions

894 ABSTRACTS

2015102400

Experimental database for surf-riding and broaching-to quantification based on captive model tests in waves. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 3, p 94 [11 p, 14 ref, 1 tab, 11 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Horel, B., Guillerm, P-E., Et al English

With the aim of better understanding the phenomena of surf-riding and broaching for small service ships, a 6DOF numerical-experimental hybrid model based on semi-captive model tests in following waves has been created. Since a system based model is used, experiments are required in order to bring the hydrodynamic interactions between hull and water. In this paper, several semi-captive model tests in calm water and in following waves using a 1/10 scaled model of a trawler’s hull will be presented. When navigating in astern seas, three modes of motion can be observed: the ship is overtaken by a wave, the ship is surfing a wave and the ship overtakes a wave.

Broaching Model tests Numerical models Ship motions

2015102401

Air pressure scale effects during damage model tests. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 3, p 105 [5 p, 3 ref, 12 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Lee, G.J., Walrre, F. van, Et al English

The Stability in Waves committee of the 27th ITTC has investigated the significance of scale effects in air pressure on flooding model tests under atmospheric conditions. For this purpose, the committee classified the flooding cases into the trapped air case and vented air cases, and investigated the flooding process for a simple geometry using the state equation of air and the orifice equation. As a result, the committee concluded that the scale effect is large for the case of

trapped air and small vent area. For the other cases, the effect is small and can therefore be neglected in the model test of a damaged ship. The committee further proposed some guidelines that can be used to reduce the scale effect of air pressure.

Air Flooding Model tests Pressure Scale effect

2015102402

Experimental and numerical study on predicting method of parametric rolling in regular head seas. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 3, p 117 [9 p,16 ref, 1 tab, 8 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Lu, J., Gu, M., Umeda, N. English

The methods to be used for direct stability assessment of parametric rolling are now under development by the International Maritime Organization (IMO) in the second generation intact stability criteria. In order to provide a reliable numerical method for predicting parametric rolling, firstly, free running experiments and partially restrained free running experiments were conducted to examine the effect of surge motion on parametric rolling and the effect of parametric rolling on heave and pitch motions in regular head seas. Secondly, the surge-roll coupled model with added resistance taken into account is used to predict parametric rolling in which the restoring variation is estimated with coupling from the vertical motion and diffraction effects, which are obtained with a strip theory. Thirdly, a coupled heave-roll-pitch mathematical model based on a nonlinear strip theory is used to calculate heave and pitch motions in regular head seas with parametric rolling taken into account. Finally, time-domain heave and pitch motions are analysed in the frequency-domain by the Fourier transformation. The results of free running experiments, partially restrained free running experiments and simulations using the C11 containership show that the surge motion on parametric rolling is general small in regular head

ABSTRACTS 895

seas and heave and pitch motions are distinctly affected by parametric rolling and the pitch and heave motions in experiment include subharmonic component when parametric rolling occurs.

Mathematical models Model tests Pitching Rolling Surging

2015102403

Experimental and numerical study on roll restoring variation using the C11 containership. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 3, p 126 [7 p, 13 ref, 1 tab, 6 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Gu, M., Lu, J., Wang, T. English

The vulnerability criteria and direct stability assessment on parametric rolling and pure loss of stability are now under development by the International Maritime Organization (IMO) in the second generation intact stability criteria. Roll restoring variation is a key factor for both criteria and model experiments and simulations are conducted to study the roll restoring variation in waves. Firstly, captive model experiments in which heave and pitch motions are free and other motions are restrained with a constant heeling angle are conducted to measure roll restoring variation in following and head seas for parametric rolling and pure loss of stability. Secondly, the roll restoring variations of Froude-Krylov calculation by a static balance method and a strip method of heave and pitch motions are carried out in following and head seas, and the dynamic effect of radiation and diffraction force on restoring variation are also calculated. Finally, the rule of roll restoring variation in following and head seas is pointed out by experiments and simulations and the numerical methods are also validated through the comparisons between the model experiments and the

simulations using the C11 containership for the vulnerability criteria and direct stability assessment on parametric rolling and pure loss of stability.

Containerships Mathematical models Model tests Rolling Stability

2015102404

Prediction of irregular motions of free-fall lifeboats during drops from damaged FPSO. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23090 [11p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911466 Tregde, V., Nestegård, A. English

A Free Fall Lifeboat (FFLB) which is evacuating from a damaged host in storm conditions must to be able to safely run away from the host. For a safe evacuation, the FFLB must first of all avoid irregular motion (“log dive”), and secondly resurface at a sufficient distance away from host (headway) to be able to run away. The design standard requires a controlled motion trajectory for the FFLB in waves. A drop simulator for random drops of FFLBs from a floating host in storm conditions, intact or damaged has been developed. Time histories of the host motions are generated and random drops of the FFLBs are done during three hour duration of each sea state. The FFLB point of impact in the wave is identified and the local wave height, wave length and hit point in the wave cycle is found for each of the impact points. A structured database with results from a large number of Computational Fluid Dynamics (CFD) simulations has been made for a specific FFLB. In this CFD screening process the lifeboat has been dropped with variations in wind and waves, as well as varying conditions of host during launch. This database forms the basis for a regression analysis used to estimate responses for each drop of

896 ABSTRACTS

free fall lifeboat found from the drop simulator. This study proposes a definition and a method to identify irregular motions for FFLBs, and this definition is used as a motion indicator in the regression analysis. By using the proposed motion indicator, the regression analysis provides percentage of acceptable vs. non-acceptable motion trajectories for a given intact or damaged host during a storm condition. The worst conditions are found, and can be used for further analysis of headway, i.e. the ability of the FFLB to escape from the host after resurfacing.

Computational fluid dynamics FPSOs Lifeboats Motion

2015102405

Manoeuvring in waves based on potential theory. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23826 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912074 Schoop-Zipfel, J., Abdel-Maksoud, M. English

The forces acting on a manoeuvring ship are determined with the in-house potential code panMARE. For slender ships with salient hull features, the forces and moments can be captured by properly treating the shed vorticity. For blunt ships it is not possible to directly determine the strength of the vorticity and the position where it leaves the hull. Therefore, it is easier and not less accurate to account for separation forces via semi-empirical formulae. These corrections are based on slender body theory or extensive RANS computations. The mass forces can be determined directly by potential theory. Forces and moments due to rudder and propeller are calculated using state-of-the-art procedures. Arbitrary manoeuvres can be simulated by using the equations of motion. With the applied corrections a satisfactory agreement with model test results can be obtained. Wave excitation forces can be introduced to

incorporate the influence of sea states. These forces are determined with strip theory. While the forces agree well with measured data, a deviation can be observed in the motions.

Manoeuvring Mathematical analysis Wave forces on ships

2015102406

Research on the coupling effects between ship motions and sloshing. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23846 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912077 Zhao, W., Yang, J., Et al English

Floating Liquefied Natural Gas (FLNG) facilities, which are a new type of floating platform, have been developed as an alternative to long pipelines for the exploitation of stranded offshore fields. FLNG vessels will be subjected to very complicated and onerous sea states in some regions and very severe motion responses must be avoided. The vessel motion can induce internal tank sloshing, which can in turn affect the global motion response of the vessel. This coupling response is of great importance for the safe design and operation of FLNG facilities in real sea states. This paper investigates the coupling effect between FLNG roll motions and sloshing. Model tests are carried out for a section of an FLNG vessel containing a tank excited in roll by band-limited white noise waves. During the model tests, the FLNG model is ballasted with fresh water and equivalent steel ballast weights respectively, to quantify the coupling effects due to the internal sloshing. Time histories of the global motions and the internal sloshing oscillations have been measured. Statistical and spectral analyses have been carried out on the measured data. The response amplitude operators are obtained using measured motion spectra divided by the excitation wave spectrum. The influence of the

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internal sloshing on the global motions has been illustrated through the comparison of the experimental results between the liquid and solid (steel) ballast weight cases. Based on the experimental results, some conclusions regarding the coupling mechanism between FLNG motions and sloshing are drawn.

Coupled motion Model tests Rolling Sloshing

2015102407

Simulating minimum required power and manoeuvrability in adverse conditions. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23878 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912078 Sprenger, F., Selvik, Ø., Et al English

The 2002 IMO regulations regarding the turning, course keeping and stopping ability for vessels with a length greater than 100 m do not cover the presence of waves, wind and current. But their effects may significantly reduce the manoeuvring performance of ships, especially of smaller vessel types in shallow and restricted waters. Since January 2013, an additional IMO regulation is in force, covering the energy efficiency of ships by defining an Energy Efficiency Design Index (EEDI) that must not exceed a specified reference line for any new-built or converted vessel. The reference line to be met will successively be lowered in three steps. One way to meet the EEDI is a reduction of the installed power, which reduces the powering margin and may lead to significant safety issues for some ship types like smaller general cargo vessels since manoeuvring capabilities in adverse conditions, might not be sufficient anymore. Due to the unpredictability of waves, a performance assessment is certainly not feasible in full scale and systematic model test series are time consuming and expensive. It is therefore of utmost importance to develop reliable and efficient software tools that are capable to simulate and predict the seakeeping and manoeuvring behaviour of a

vessel at the design stage. In this paper, MARINTEK’s combined seakeeping/manoeuvring simulator VeSim is presented, calibrated and successfully validated by model tests with a general cargo vessel. In this software, the vessel hydrodynamics are solved taking care of both the seakeeping and manoeuvring problems simultaneously. External forces result from waves, current and wind as well as from e.g. the propulsion system and mooring lines. The pre-calculated hydrodynamic properties of the vessel include speed-dependent resistance, manoeuvring forces (mainly viscous), mass and restoring properties, damping and added mass properties (represented as retardation functions) and viscous roll damping. The manoeuvring forces are calculated using current and wave particle velocities as input in addition to the ships velocities. A simulation study with VeSim is performed to find the minimum required power for advancing in head seas as a function of wave period and wave height for a general cargo vessel. In addition, two IMO standard manoeuvres - turning circles and 10°/10° zig-zag tests - are simulated in calm water as well as one regular wave condition in order to exemplify the capabilities of VeSim.

Manoeuvrability Power requirements Simulation

2015102408

A linearized free-surface RANS method for unsteady ship maneuvering problems. 30th International Workshop on Water Waves and Floating Bodies; 12-15 April 2015; Bristol, UK. [4 p, 5 ref, 2 fig] http://www.iwwwfb.org/Abstracts/iwwwfb30/iwwwfb30_55.pdf Wooliscroft, M.O., Maki, K.J. English

The unsteady linearized free-surface condition is implemented within a numerical framework based on the Reynolds-Averaged Navier-Stokes equations. The target application for the novel solver is the simulation of ship manoeuvring, and in particular, cases in which the fluid viscosity and turbulence are important and the rudders and propellers are moving. The method is more computationally efficient than viscous-flow methods that satisfy the fully-nonlinear free-surface conditions and is computationally equivalent to a numerical method that solves for a

898 ABSTRACTS

velocity potential via discretization of the flow domain (not the domain boundary). The new solver is validated by comparing with results from other numerical methods and physical experiments of the waves generated by a heaving catamaran, and the force on the hull of the naval destroyer 5415 moving with prescribed horizontal-plane motion.

Computational fluid dynamics Free surfaces Manoeuvring 2015102409 Green water on FPSO analysed by a coupled potential-flow-NS-VOF method. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23913 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912080 Pakozdi, C., Östman, A., Et al English

Nowadays frequent use of FPSOs for offshore oil production in areas prone to green water events has increased the industry’s focus on wave-induced impact loads as an important design parameter. This is a complex hydrodynamic problem where simplified engineering methods are often used in connection with model testing. Various efforts have been presented during the recent 10–15 years to establish reasonably good industry design tools, while the use of fully nonlinear methods and CFD is still in its development. The main focus of this paper is to investigate the potential of a simplified coupled method between a potential theory based Green Water engineer tool (Kinema3) and the commercial CFD tool Star-CCM+ based on its Navier-Stokes Solver (NS) and the Volume of Fluid (VOF) method. Results from a case study application on a large FPSO are validated against model test data. The case study contains analyses of the FPSO in long crested regular seas, both in fixed and in moored conditions. Three different heading directions are included. The approach for modelling green water events uses a Finite-Volume-VOF method with a complex velocity inlet boundary condition. Thus the Kinema3 engineering tool is used to generate simplified spatio-temporal inlet conditions from the relative wave elevation and wave kinematics at the bulwark, based on linear potential theory combined with nonlinear random wave kinematics. The VOF method is then used to model the detailed flow on deck, including

impact forces on deck structures. Kinema3 can also generate simplified estimates for the peak water height, velocity as well as impact force values assuming an extended dam-break approach together with a simplified, local 2D deck layout, and comparisons to the CFD results show an overall fairly good agreement although flow details on deck can of course not be expected to be modelled that well. Comparisons of the above results to model test data show good agreement both for the relative wave height, water height and impact force level, in regular and irregular waves. Detailed time histories, including force rise time, from the coupled Kinema3 - Star-CCM+ CFD simulation analysis are quite similar to the measured ones. The CPU time consumption for the coupled simulation is moderate compared to a full CFD simulation of the FPSO in waves. Hence the achieved calculation time and the simplicity of the simulation setup of the numerical simulation makes this method an interesting candidate for industrial use.

Computational fluid dynamics Deck wetness FPSOs Wave loads

2015102410

A fully nonlinear RANS-VOF numerical wave tank applied in the analysis of green water on FPSO in waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23927 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912082 Östman, A., Pakozdi, C., Et al English

This paper presents numerical simulations of Green Water events and wave impact on a FPSO. The simulations are performed at model scale and the results are compared against experimental model test results. The commercial Star-CCM+ CFD software is used in the simulations. The incoming waves are modelled using 5th order Stokes theory, as implemented in the CFD software. Both fixed and free floating FPSO are considered. The moving FPSO are modelled using Chimera overset mesh technology. The vessels is free to move in heave and pitch at 180 (head sea), roll and heave at 270 (beam sea), while roll, pitch and heave is released at 225

ABSTRACTS 899

(quartering sea). The computed water height on the deck and the relative wave height in vicinity the vessel are compared against model test results at several positions. Also the impact force on load cells blocks located at the deck of the vessel is computed and compared against model test results. The comparison of the time histories of the water elevation and load histories are in reasonable agreement with the measured time series. The number of grid cells range from 7M for the simulations at head sea, where flow is assumed to be symmetric, to 21M for the simulations at quartering sea. Total wall clock simulation time was about 10days for the most computationally demanding cases, which are the quartering sea simulations. This includes simulation of 12 wave periods with the ship fixed, and thereafter 8 wave periods of the free floating vessel. The computations show that CFD tools can be used as a research tool when studying the physics of green water and wave impact events. However, due to time CPU demanding simulations, this type of CFD analysis are not yet a practical tool for parametric design studies and deck structure optimisations.

Computational fluid dynamics Deck wetness FPSOs Wave loads

2015102411

Green water loads determination for FPSO exposed to beam sea conditions. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-29478 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912084 Carvalho e Silva, D.F. de, Rossi, R.R. English

Considering new offshore frontiers for oil exploration and production, especially the Santos Basin region, FPSOs will be exposed to more severe wave conditions. This scenario requires careful analysis with respect to the green water phenomenon. The complex physics involved in the water-on-deck flow implies on several uncertainties regarding green water loads analysis. Taking into account model tests, CFD simulations and analytical formulations, this paper aims to simplify the green water loads determination, proposing a methodology to estimate these loads considering the water elevation above deck measured

from experiments or numerical tools. In order to accomplish this objective, CFD simulations with different solvers were run for a benchmark case, showing that it is a suitable approach for a global result in impact dam break cases. After that, a special boundary condition was calibrated to represent model test results of water propagation in a FPSO deck exposed to beam sea in terms of water elevation. Using this CFD model, the loads on exposed structures was determined and compared against the dam break analytical formulation, which was modified to take into account the gap between each structure and the deck. Finally some vane type protection structures were simulated and their efficiency in partially obstructing the water-on-deck flow was evaluated. As a global result from all these analysis, a more comprehensive strategy for green water loads determination is proposed.

Beam seas Computational fluid dynamics Deck wetness FPSOs Wave loads 2015102412

Experimental investigation vs numerical simulation of the dynamic response of a moored floating structure to waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24064 [12 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912099 Dessi, D., Minna, S.S. English

A combined numerical/theoretical investigation of a moored floating structure response to incoming waves is presented. The floating structure consists of three bodies, equipped with fenders, joined by elastic cables. The system is also moored to the seabed with eight mooring lines. This corresponds to an actual configuration of a floating structure used as a multipurpose platform for hosting wind-turbines, aquaculture farms or wave-energy converters. The dynamic wave response is investigated with numerical simulations in regular and irregular waves, showing a good agreement with experiments in terms of time histories of pitch, heave and surge motions as well as of the mooring line forces. To highlight the dynamical behaviour of this complex configuration,

900 ABSTRACTS

the proper orthogonal decomposition is used for extracting the principal modes by which the moored structure oscillates in waves giving further insights about the way waves excites the structure.

Dynamic response Experimentation Floating structures Moored structures Numerical models

2015102413

Green water on FPSO predicted by a practical engineering method and validated against model test data for irregular waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24084 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912101 Schiller, R.V., Pâkozdi, C., Et al English

This paper presents a series of numerical analyses performed with the potential theory-based Green Water engineer tool KINEMA3. KINEMA3 was designed to predict wave-induced impact loads on FPSOs in steep irregular waves, and for use in design load analysis. The purpose of the study presented herein is to validate KINEMA3 green water (deck overtopping) predictions in nonlinear irregular waves with results from model tests. Comparisons are made for a selection of irregular wave cases, for two choices of anchoring conditions (free floating vessel and fixed vessel) and for three wave headings (180°, 225° and 270°: head, quartering and beam seas, respectively). KINEMA3 statistical green water predictions present a general good agreement with observations from the TPN model tests for all wave cases, headings and mooring conditions. Overall, observed trends for occurrence of green water and standard deviation/maximum of relative wave height are successfully reproduced by KINEMA3. In agreement with model test results, it is predicted that green water occurs more frequently for a free floating vessel and for beam seas. Additional comparisons between KINEMA3 predictions using different FPSO panel models (low-order and high-order models) present negligible differences with respect to green water estimates. The results presented demonstrate the robustness of the tool towards the prediction of green water for variable wave headings and sea states,

and highlight the capability of KINEMA3 to be employed as an engineering-like tool for fast and multiple estimates of green water in early design studies.

Deck wetness FPSOs Irregular waves Numerical analysis Wave loads

2015102414

Transient wave packets: new application in CFD methods. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24101 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912107 Clauss, G.F., Stuppe, S., Dudek, M. English

Detailed knowledge of motion and seakeeping behaviour in an early design stage is indispensable in modern layout of marine offshore structures. Therefore, numerical methods are used to calculate the Response Amplitude Operators (RAO), which are generally based on potential theory or the Reynolds Averaged Navier Stokes Equation (RANSE). Calculations with potential-codes are commonly used, well established and time-saving. Main disadvantages are the neglect of viscous effects and the hull structure above the still water level. By using RANSE-methods, these nonlinear effects can be investigated in detail, but at the price of calculation time and extensive grid generation. To achieve sufficient RAOs in frequency domain, time-consuming and intensive calculations would be necessary with these CFD-methods, using sea state applications with regular or irregular waves only. Therefore, these methods are not convenient for standard motion analysis by now. Transient Wave Packets (TWP) represent an approved method at model tests, revealing the entire RAO for any offshore structure within one single, short test run. Main advantage of this technique is the accurate predictability and short superposition in space and time. Containing all elementary wavelengths of the generated initial wave spectra, the TWP-method could be used in RANSE-methods, implementing all necessary initial conditions to the CFD-solver. To reduce the calculation effort to a minimum in space

ABSTRACTS 901

and time, the superimposed wave train is generated near the investigated offshore structure by using modified, linear wave theory in spatial domain. To present this method by means of a practical example, the motion and sloshing behaviour of an offshore LNG-carrier (LNGC) are investigated in detail. For validation purpose, all results are compared to model tests, as well as numerical results of the potential theory solver WAMIT.

Computational fluid dynamics Seakeeping Transients

2015102415

Experimental study of forces exerted on ships due to the vertical walls of navigation channels. TransNav, v 9 n 2, June 2015, p 199 [5 p, 8 ref, 2 tab, 12 fig] http://www.transnav.eu/Article_Experimental_Study_of_Forces_Kazerooni,34,573.html Kazerooni, M.F., Seif, M.S. English

Ship manoeuvring in restricted waters of harbour basins and navigation channels has been a concern in recent years due to the sudden increase of ship’s size. When the ship enters a navigation channel the lateral boundary of the channel exerts a transverse force and turning moment on the ship hull. These forces are important in the analysis of safety of ship navigation in the channels. Ship model testing in a towing tank is a reliable method to evaluate these forces. Therefore systematic model tests are held for modelling the forces exerted on a tanker ship model traveling alongside a vertical wall. A database of the interaction forces is developed and the specific hydrodynamic effects related to the phenomena are discussed. The results can be used for simulation of ship manoeuvring and assessment of safety limits for navigation of ships alongside quay walls and breakwaters.

Manoeuvring Model tests Navigation channels Restricted waters Wall effects

2015102416

Effect of ship forward speed on ship response statistics in extreme seas. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24695 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911711 Guo, B., Bitner-Gregersen, E.M. English

Earlier investigations have indicated that proper prediction of nonlinear responses due to nonlinear waves is important for ship safety in extreme seas. Nonlinearities may increase significantly ship responses in steep sea-states, particularly when rogue waves are present. So far most of the model tests in rogue waves have been performed without ship forward speed. Therefore the effect of forward speed on ship responses is still not sufficiently investigated. This study addresses this topic by taking an LNG tanker as an example. Ship responses of the LNG tanker with/without forward speed are studied with both model tests and numerical simulations. The model test is carried out in the sea-keeping tank of the Technical University of Berlin and numerical simulations are performed using the 3D Panel code. The statistical uncertainty of the ship responses due to different time spans is investigated also. The study shows that ship forward speed increases the ship motions and hogging moment. The change of sagging moment due to the forward speed is very small at slow speed. After the ship forward speed is increased to a certain value, the sagging moment increases significantly with ship speed.

Extreme seas Forward speed Ship response

902 ABSTRACTS

2015102417

Wave drift forces and resonance analysis on two ships arranged side by side. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24369 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912120 Zhang, Y., Yu, D., Et al English

In recent years, with the development of new ships and further utilization of marine resources, multi-body floating systems are widely used in practice. Compared with the single floating body, the movement in multi-body floating system is not only affected by the external environment, but the interaction between the bodies cannot be neglected. So analysis of hydrodynamic performance of a multi-body floating system is of great importance. In this paper, a multi-body system consisting of two side-by-side ships is studied. The code AQWA® is used for its hydrodynamic performance analysis in frequency domain. Its hydrodynamic parameters are compared with those of the related single-ship system and the difference is obvious. The two-ship system shows a peak in motion different from single-ship system at some frequencies and its wave exciting forces have period effects. Also, negative values appear in added masses, which never occur for a single-body floating system. When the gap between the two ships is changed, there is a significant trend that the wave frequency of the peak value decreases with the gap size between the two ships. In addition, this paper also discussed the length of wave and distance of ships ratio that the motion resonance usually happens. Through the analysis of this dimensionless parameter, a conclusion about resonance between two parallel ships is deducted.

Drift forces Multibody systems Resonance

3.4 FLUID STRUCTURE INTERACTION

2015102418

Effect of turbulence modelling on 3-D LES of transitional flow behind a circular cylinder. Ocean Engineering, v 100, 15 May 2015, pp 19-25 http://www.sciencedirect.com/science/article/pii/S0029801815000724 Kim, S., Wilson, P.A., Chen, Z-M. English

Results of a numerical evaluation of transitional flow behind a circular cylinder are presented. Three-dimensional calculations are performed in a frame of large eddy simulation at a Reynolds number of 41,300 based on the free stream velocity and cylinder diameter for which previous experimental data is available for comparison. The flow in the transitional regime is characterized by the presence of multiple flow scales such as small-scale shear-layer vortices in freely separating boundary layers and large-scale vortex motion in the wake. Three different subgrid scales, namely the Smagorinsky, k-equation and dynamic k-equation models, are applied in order to evaluate such a challenging flow field at the higher Reynolds number. The effects of the subgrid scale modelling on the main wake parameters and mean flow statistics are discussed in detail and compared to the available experimental measurements for the challenging flow regime.

Cylindrical bodies Mathematical models Transition flow Turbulence

2015102419

Quantification of hydroelasticity in water impacts of flexible composite hull panels. Ocean Engineering, v 100, 15 May 2015, pp 117-125 http://www.sciencedirect.com/science/article/pii/S0029801815000876 Allen, T., Battley, M. English

Understanding the effect a flexible structure has on the loads and responses during slamming events will improve the design process for high speed marine craft. Design of hulls is typically undertaken on the assumption that the pressures applied are the same as if the hull was rigid. In reality the loads may vary due to the hydroelasticity resulting from the fluid structure interaction during the impact. This work characterises the variations in both applied pressure

ABSTRACTS 903

and panel response due to the hydroelasticity. Impacts have been undertaken using a purpose built servo-hydraulic slam testing system with impact velocities up to 6.0 m/s and a deadrise angle of 10°. The unsupported panel area was set at approx. 1000×500 mm with simply supported boundaries along all four edges. Clear trends between a panel’s flexibility and the total force and applied pressure have been observed. The changes in both loads and responses are largest at the centre and chine edge of the panel and can be related to the regions of the most significant changes in local velocity (centre) and deadrise angle (chine). Changes in the loads and responses for sandwich constructions can be attributed to the shear stiffness and shear factor as well as the flexural rigidity.

Composite materials Flexible materials Hydroelasticity Impact loads Slamming

2015102420

CFD based computation of bow impact loads for buckling assessment. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 4 [9 p, 13 ref, 2 tab, 10 fig] https://www.crcpress.com/product/isbn/9781138027893 Oberhagemann, J., Radon, M., Et al English

Bow slamming impact pressure forces acting on larger areas are of primary interest for dimensioning the larger supporting bow structures of ships. Although computational fluid dynamics methods are able to reliably predict bow impact loads for a given wave situation, large uncertainty is related to the identification of relevant scenarios. These need to assure sufficient conservatism, yet shall not lead to excessively large loads. This paper compares application of conditioned wave sequences with more traditional equivalent design waves. A rough estimate of long-term expected maximum bow impact loads is made based on available simulation data. Further, structural stresses resulting from slamming pressure loads are compared with rule based bow pressure

loads. Rule based results are in general exceeding the stresses found from simulations. The work was performed as part of a joint development project of DSME and DNV GL.

Bows Computational fluid dynamics Slamming Wave loads

2015102421

Wave-induced responses of a bulk carrier in heading and following seas. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 7 [8 p, 13 ref, 3 tab, 12 fig] https://www.crcpress.com/product/isbn/9781138027893 Wang, X.L., Liu, R.M., Hu, J.J. English

A bulk carrier is introduced in this paper to study its low- and high-frequency responses both in heading and following seas. Effects of four loading conditions on wave-induced responses are investigated by a 3-D hydroelasticity method. Moreover, experimental results of two loading conditions are also presented to test and verify the theoretical results of the 3-D method. It is shown that loading conditions have great influences on the wave-induced responses. Springing and whipping behaviours will be influenced obviously by high forward speeds. Small draft in ballast condition will cause high peak in 2-node vertical vibrations. 3-D hydroelasticity theory can make up the limitations in experiments because of the high cost and the capacity of facility. Results of this paper show the necessity of taking into adequate consideration of high-frequency vibrations on strength and fatigue damage of ship structure in the bulk carrier’s design stage.

Bulk carriers Hydroelasticity Wave loads on ships

904 ABSTRACTS

2015102422

Slamming impact loads on high-speed craft sections using two-dimensional modelling. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 9 [9 p, 15 ref, 5 tab, 13 fig] https://www.crcpress.com/product/isbn/9781138027893 Camilleri, J., Taunton, D.J., Temarel, P. English

The slamming impact loads experienced by high-speed craft travelling in rough seas are numerically investigated by analysing the idealized problem of a two-dimensional rigid wedge impacting an initially calm water surface. The authors use the commercial CFD software Star CCM+, which is based on the Finite Volume (FV) method and an interface capturing scheme of the Volume-of-Fluid (VOF) type. The set-up of the numerical model is described in detail. The influence of mesh size, time step, and other numerical parameters such as inner iterations and relaxation factors, as well as three-dimensional modelling, on the solution is studied in a systematic manner. Comparisons against published experimental data show favourable agreement.

Computational fluid dynamics High speed vessels Impact loads Slamming

2015102423

Non-linear hydroelastic and fatigue analyses for a very large bulk carrier. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 10 [11 p, 28 ref, 15 tab, 12 fig] https://www.crcpress.com/product/isbn/9781138027893 Cristea, B., Mocanu, C.I., Domnisoru, L. English

The paper is focused on the ship hull dynamic and fatigue analyses, in order to predict the preliminary design ship life. The ship dynamic analyses are carried out with own program codes package DYN, based on linear and non-linear hydroelasticity theory. As study case there is considered a very large double hull bulk carrier. The numerical approach includes three main steps: the global-local strength analysis on equivalent quasi-static head waves, the hydroelastic response analysis on head irregular wave and the

cumulative damage factor fatigue analysis. Based on 3D/1D-FEM models, the stress 3D/1D correlation factors on structural details are obtained. The 2D/1D dynamic analyses outline the extreme wave loads, induced by slamming-whipping and springing hydroelastic responses. The study is focused on the influence of the hydroelastic responses on the fatigue strength assessment, making possible to obtain a more realistic ship preliminary structural service life prediction for a very large bulk carrier.

Bulk carriers Dynamic analysis Fatigue life Hydroelasticity Numerical analysis

2015102424

Hydroelastic analysis of a flexible barge in regular waves using coupled CFD-FEM modelling. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 11 [9 p, 11 ref, 5 tab, 8 fig] https://www.crcpress.com/product/isbn/9781138027893 Lakshmynarayanana, P., Temarel, P., Chen, Z. English

The aim of this paper is to investigate the wave-body interaction of flexible floating bodies by coupling RANS/CFD and Finite Element software. A combination of overset and morphing approaches and finite volume solution to allow for the motion of a barge at the free surface is used. Results are presented for the motion response of the Three-Dimensional (3-D) barge, treated both as rigid and flexible body, in regular head waves using STAR-CCM+, the latter carried out by a two-way coupling between Star-CCM+ and Abaqus. To illustrate this application, the structure of the flexible barge is modelled as a beam, in line with the flexible backbone model used in experiments. The RAOs of vertical displacements, at a number of positions along the barge, calculated using this coupling technique is compared against experimental measurements and Two-Dimensional (2-D) linear hydroelasticity predictions.

Computational fluid dynamics Finite element method Flexible structures Floating bodies Hydroelasticity

ABSTRACTS 905

2015102425

Liquid sloshing analysis for independent tank with elastic supports. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 16 [9 p, 14 ref, 3 tab, 15 fig] https://www.crcpress.com/product/isbn/9781138027893 Liu, W., Xue, H., Tang, W. English

The sloshing characteristics are investigated in the independent tank with elastic supports. A 2D coupled algorithm involving the Hilber-Hughes-Taylor implicit method for the tank motion and the VOF method for the fluid is proposed and then validated by comparing with the experimental results. By conducting coupled calculation and comparing the numerical results with those obtained by ignoring the elastic impact, obvious differences of the tank motion and liquid sloshing are found between the two models. The stiffness of elastic support has a significant impact on the sloshing load. Precisely, with the increase of the stiffness, the sloshing load keeps growing dramatically and reaches its peak at the resonant point, before dropping continually and eventually levelling off to a constant value, which is coincident with the sloshing load without considering the elastic influence. An efficient and effective method is finally presented for forecasting the sloshing load of independent tank with elastic supports.

Elastic bodies LNG tanks Sloshing Supports

2015102426

CFD applications in offshore engineering. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25930 [12 p] https://www.onepetro.org/conference-paper/OTC-25930-MS Darvishzadeh, T., Sari, A. English

Offshore engineering applications generally require interactions between offshore structures and fluids in the form of oceanic flows or blast waves. A correct estimation of the forces caused by these flows is crucial in designing highly reliable structures to be used in offshore environment. Computational Fluid

Dynamics (CFD) has been used to analyse the fluid behavior and its influence on offshore structures by solving the equations of fluid motion. However, resolution of all spatial and temporal scales of the flow requires very time-consuming and complicated CFD simulations. This paper demonstrates various applications of simplified CFD methods in solving problems associated with offshore technologies. The paper presents results of shock wave interaction with modular buildings and large pipes using Fluid-Solid Interaction (FSI) method and comment on their structural behavior and damage levels. Moreover, the impact of a drop object on a subsea pipeline protection structure is investigated using FSI and structural analysis. Furthermore, the air temperature increase inside a modular building is estimated using computational analysis of free convection coupled with heat transfer analysis of the modular building. Finally, the paper reports CFD results of velocity enhancement of offshore columns and the hydrodynamic interaction amongst groups of cylinders. Star-CCM+ is used for most of the CFD computations and is coupled with Abaqus for solving FSI problems. The results demonstrate how critical parameters such as fluid forces could be computed using simplified CFD approaches while often coupled with detailed structural analysis using finite element method to reduce their conservatism.

Computational fluid dynamics Fluid structure interaction Offshore engineering

2015102427

Higher order hydrodynamic interaction between two slender bodies in potential flow. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 249-256 http://link.springer.com/article/10.1007/s00773-014-0275-0 Kadri, U., Weihs, D. English

In this paper, the authors apply the slender body theory to study the effect of higher order hydrodynamic interactions between two slender bodies of revolution moving in close proximity, in an unbounded, inviscid, and incompressible fluid. The authors compare between leading and second-order approximations, as well as approximate and exact separation distances. The total solution is found to be valid for both small and large lateral separation distances. The contribution of the higher order forces is found to be relatively small for large separation distances, though significant for small separation

906 ABSTRACTS

distances. Comparisons with measurements and simulations are satisfactory.

Interactions Multibody systems Potential flow Slender bodies Slender body theory

2015102428

Viscous and potential forces on an advancing surface-piercing flat plate with a fixed drift angle. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 278-291 http://link.springer.com/article/10.1007/s00773-014-0282-1 Ommani, B., Faltinsen, O.M. English

Transverse force and yaw moment acting on a surface-piercing flat plate with yaw angle and forward speed are studied. Following the Froude hypothesis, the problem is decomposed into a tail-separated forward flow and a bottom-tip-separated cross-flow part. The objective is to quantify the role of different components in the resulted force and moment acting on the plate. A 3D potential flow code using distribution of Rankine sources and dipoles is used to solve the linear potential flow problem. The free-surface boundary condition is linearized based on the undisturbed flow velocity (Neumann–Kelvin linearization). The plate’s trailing-edge flow separation is modeled using a dipole distribution behind the plate on a linearized vortex sheet. The force and moment due to the cross-flow separation from the plate’s bottom tip are calculated by means of a slender body cross-flow method with a rigid free-surface boundary condition. Hence the free-surface effects are confined in the forward flow problem and neglected in the cross-flow problem. Simulations are carried out for different aspect ratios and drift angles. The plate’s thickness is taken into account. Convergence and sensitivity studies are performed carefully. Results are compared with previous experimental and numerical studies. The importance of the second-order forces and validity of the linear assumptions are touched upon. The overall agreement

of the results is acceptable. The relative importance of the two viscous and potential components is studied. It is shown that the decomposed problem could follow the experimental results up to a relatively high Froude number.

Crossflow Forces Slender bodies

2015102429

Modeling of fluid–structure interaction for simulating vortex-induced vibration of flexible riser: finite difference method combined with wake oscillator model. Journal of Marine Science and Technology, v 20 n 2, June 2015, pp 309-321 http://link.springer.com/article/10.1007/s00773-014-0284-z Doan, V-P., Nishi, Y. English

This paper proposes a numerical simulation method for the dynamic motion of a flexible riser pipe undergoing vortex-induced vibration (VIV). The method is based on a finite difference scheme for solving nonlinear structural dynamics of the pipe and wake oscillator model for quantifying vortex-induced forces acting on the pipe, the combination of which can offer a very efficient and stable computation. To investigate the accuracy of the method, the authors performed simulations of the VIV of riser pipes under uniform flow and sheared flow conditions; and then compared obtained results with experiments of preceding works. It is consequently confirmed that the present method can simulate a couple of important aspects of the VIV of the pipes: frequency, mode shape, and amplitude of displacement of cross-flow displacement.

Finite difference method Fluid structure interaction Risers Vortex induced vibration

ABSTRACTS 907

2015102430

Modelling of wave-structure interaction of a cylinder in irregular sea waves with vessel motions using coupled transient CFD and diffraction methodology. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25793 [13 p] https://www.onepetro.org/conference-paper/OTC-25793-MS Jia, D., Agrawal, M., Schofield, P. English

This paper is a continuation of previous paper where a parametric study was performed for wave- structure interaction on a hollow cylinder in regular sea waves without vessel motions, and the effect of waves and current on the motion of the cylinder and the associated forces using a high fidelity methodology to couple CFD with diffraction analysis. This approach was demonstrated for predicting the motions and loads of subsea equipment and structures during offshore operations. Instead of relying on simplified equations or empirical formulations to calculate and estimate the hydrodynamics coefficients, or using steady-state CFD simulation on a stationary equipment and structure to predict drag and added masses on submerged structures in traditional approaches, this methodology couples the transient CFD with diffraction analysis. In this paper, the authors extend the solution to include wave-structure interaction in irregular sea waves and vessel motions. Irregular waves are modelled using a JONSWAP wave spectrum. Simulations are performed to investigate effect of significant wave height, peak wave frequency (time period) of irregular sea waves, and vessel motions on the motion of a hollow cylinder in irregular sea waves. The results are compared with the traditional approach in current practice. The time domain diffraction simulation is coupled with multiphase CFD simulation of subsea equipment and structures in waves. A transient CFD model with rigid body motion for the equipment and structure calculates added masses, forces and moments on the equipment and structure for diffraction analysis, while diffraction analysis calculates linear and angular velocities for CFD simulation. The results provide better understanding of structure motion and associated forces in waves using this coupled methodology. The coupled methodology eliminates the inaccuracy inherited from assumed or calculated hydrodynamic properties that are obtained by using simplified equations or empirical formulations, or by using steady - state CFD analyses in traditional decoupled approaches. This coupled methodology has potential applications

in analyses of the motions of subsea equipment and structures in waves during offshore operations.

Computational fluid dynamics Cylindrical bodies Fluid structure interaction Irregular waves Ship motions

2015102431

Predicting internal solitary wave loads on spar platforms. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25904 [11 p] https://www.onepetro.org/conference-paper/OTC-25904-MS Huang, W., You, Y-x., Li, W. English

Internal solitary waves (ISWs) can impose significant loads on offshore structures. During the past several decades, ISWs have led to a series of incidents. With large draughts, spar platforms can be affected by ISWs; therefore, the ISW effect should not be neglected during the design, installation and operation in areas where ISWs can occur. However, there is a gap in research into this area with only a few preliminary studies published so far. In this paper, a series of experiments are carried out with a spar platform model in a large-scale stratified tank to investigate interaction characteristics of ISWs. Based on a two-layer ISW theory, a simplified theoretical model is established for predicting the ISW loads on a spar platform. It is shown that the horizontal ISW loads consist of drag and inertia components, which can be calculated using the Morison's equation, while the vertical loads are mainly the vertical Froude-Krylov force, which can be obtained by integrating the ISW-induced dynamic pressure over the spar bottom. By fitting theoretical results with experiments, specific formulas are established to determine two empirical coefficients in Morison's equation under ISW conditions, which are different from traditional methods. The numerical results from this method show good consistency with experimental results on both the amplitude of the loads and the time varying characteristics.

Offshore platforms Solitary waves Wave loads on structures

908 ABSTRACTS

2015102432

Numerical study of the flow-induced vibration of two equal-diameter cylinders in tandem with varying the mass ratio. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23200 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911472 Tofa, M.M., Maimun, A., Et al English

Mass ratio is an important parameter that influences the vortex-induced vibration of circular cylinder, especially for a two degree of freedom system. Numerical simulations have been performed for two equal-diameter cylinders with different mass ratios in tandem arrangement which are subjected to uniform flows in subcritical flow regime. The distances between the upstream and downstream cylinders were three and four times of the cylinder diameter. The purpose of this study is to investigate the effect of upstream cylinder’s mass ratio on the vibration of downstream cylinder. The shear stress transport detached eddy turbulence model has been used for simulating the turbulent flow around the two cylinders. The numerical results of a single cylinder subjected to 2DOF vibration have been compared with the experimental results available for such cases to validate the present study.

Cylindrical bodies Numerical models Vortex induced vibration

2015102433

Investigation of VIV suppression effect of the finned cylinder in subcritical flow. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23369 [9p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911482 Wang, Y., Liu, X., Et al English

The two-dimensional fluid-structure numerical model was developed to investigate the VIV suppression effect of the fined cylinder in subcritical flow (2000<Re<12000). The simulation of the flow field is performed by solving RANS equations with standard

k-ε turbulence model. And the finned cylinder is modelled as a mass-spring system. The fluid-structure interaction of the finned cylinder in a uniform stream is numerically simulated by applying the displacement and stress iterative computation on the fluid-structure interfaces. The Arbitrary Lagrangian Eulerian (ALE) method and leader-follower method were combined together to keep a good quality of the fluid domain mesh for large displacements of fluid-structure interface. The vortex induced vibration of smooth cylinder was firstly simulated and compared with the experimental and numerical results of available literatures. The cylinder with Δ60-fins (consists of three splitter plates of 0.2D depth with splitter plate angle of 60° equally spaced on the cylinder surface) was investigated. The vortex shedding mode, vibration response, vibration frequency, and lifting force for the cylinder with Δ60-fins were analysed and compared with smooth cylinder. The numerical results show that the cylinder with Δ60-fins can significantly interfere the vortex shedding and synchronization by reducing the lateral spacing of the initial large eddy. The remarkable decrease of response amplitude for cylinder with Δ60-fins is found.

Cylindrical bodies Numerical models Subcritical flow Vortex induced vibration

2015102434

Experimental study on vortex-induced vibration of floating cylinders with low aspect ratio. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23383 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911483 Gonçalves, R.T., Fujarra, A.L.C. English

Experiments regarding vortex-induced vibration on floating circular cylinders with low aspect ratio were carried out in a recirculation water channel. The floating circular cylinders were elastic supported by a set of linear springs to provide low structural damping on the system. Eight different aspect ratios were tested, namely L/D = 0.2, 0.3, 0.4, 0.5, 0.75, 1.0, 1.5 and 2.0. These aspect ratios were selected to cover the aspect ratio range of the main offshore circular platforms, such as spar and monocolumn. The aims were to understand the VIM of such

ABSTRACTS 909

platforms; due to this, the cylinders were floating, or m* = 1. The range of Reynolds number covered 2,800 < Re < 55,400. The amplitude results showed a decrease in amplitude with decreasing aspect ratio in both directions. The frequency results confirm a different behaviour for cylinders with L/D ≤ 0.5; in these cases, the cylinder free-end effects were predominant. The resonant behaviour was no longer observed for L/D ≤ 0.2. The decrease in Strouhal number with decreasing aspect ratio is also verified. All the results presented here complement the work presented previously for stationary circular cylinder with low aspect ratio presented by Gonçalves et al. (2013), Experimental Study on Flow around Circular Cylinders with Low Aspect Ratio, OMAE2013-10454.

Cylindrical bodies Experimentation Vortex induced vibration

2015102435

Numerical simulation of an oscillating cylinder in cross-flow at a Reynolds number of 10,000: forced and free oscillations. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23394 [10p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911484 Nguyen, L.T.T., Temarel, P. English

In this work, numerical simulations of flow past a circular cylinder in uniform cross-flow are investigated for three different cases: (i) a stationary cylinder, (ii) forced oscillations of a cylinder and (iii) free oscillations of a cylinder. All three cases were studied using a 2D CFD RANS code, at a Reynolds number Re = 10,000. The method adopted here is based on the Finite Volume Method using the commercial CFD package Ansys Fluent 14 with appropriate turbulence models. Comparisons with available experimental and numerical data, for all

cases investigated, show that the simulations capture essential features of the fluid-structure interaction. These comparisons include drag and lift coefficients, Strouhal number, pressure distribution, as well as amplitude of motion and frequency ratio.

Computational fluid dynamics Crossflow Cylindrical bodies Oscillations

2015102436

Vortex induced motion of TLP with consideration of appurtenances. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23420 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911487 Tan, J.H.C., Teng, Y.J., Et al English

Offshore floating platform configurations often consist of geometrically simple and symmetrical shapes which are made complicated by the presence of appurtenances such as helical strakes, tendon porches, steel catenary risers (SCR), porches, pipes, chains, fairleads and anodes on the surface of the hull. Previous studies mainly on spars show that these hull external features affect the Vortex Induced Motion (VIM) performance of the platform significantly. This is to be expected since VIM is controlled by the flow separation on the hull surface and the resulting vortex shedding patterns. Scale effects may also play a role in model tests for bare cylinders or hulls with bare cylindrical columns, whereas previous studies have shown less Reynolds dependence when appurtenances are modelled. This study investigates the effect of hull appurtenances on VIM of a multi-column floating platform, i.e. a Tension Leg Platform (TLP) designed for Southeast Asian environment. Significant difference in VIM behaviours is expected between spars and TLPs since the column aspect ratios are very different and TLPs do not have helical strakes that are commonly fitted on spars. Model testing and Computational Fluid Dynamics (CFD)

910 ABSTRACTS

simulation are used in this VIM study, with the former being the emphasis of this paper. Descriptions of the respective experimental and numerical methodologies are presented and the comparison of the results is made. Further work required to improve the model test set-up and the CFD simulation are suggested. From this study, it is shown that the effect of appurtenances on TLP VIM simulation is important and must be taken into account to obtain realistic results.

Computational fluid dynamics Model tests Platform motions Tension leg platforms Vortices

2015102437

Experimental investigation on the suppression device of VIV of a flexible riser. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23427 [17p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911488 Gao, Y., Fu, S., Et al English

Experimental investigations were conducted on a flexible riser with and without helical strakes. A uniform current was obtained by towing a riser model in a tank, and the vortex-induced vibration (VIV) suppression of strakes with different heights and pitches was studied. The results of the bare riser show that the characteristics of the synchronization of the VIV for a flexible riser have many orders, and the excited mode jumps from one to another abruptly. During the high order synchronization regime, the VIV response decreases with the increased order of the synchronization. The experimental results also indicate that the response characteristics of a bare riser can be quite distinct from those of a riser with helical strakes, and the suppression performance depends on the geometry of the helical strakes. The fatigue damage in the CF direction is of the same order as that in the IL direction for the bare riser. However, for the riser fitted with helical strakes, the fatigue damage in the CF direction is much smaller

than that in the IL direction. The experimental results also confirmed that strake height has a greater influence on the VIV response than the strake pitch, and the drag exerted on the riser increases with strake pitch and height.

Experimentation Risers Suppression Vortex induced vibration

2015102438

Dynamic coupling between top-end vessel sway and slender riser VIV in deep water. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23834 [8p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911511 Chen, W., Li, M., Et al English

The impacts of top-end motion on the riser undergoing vortex-induced vibration (VIV) are explored in this study, because the dynamic coupling between moving top-end vessel and submarine riser becomes more remarkable for a floating platform in deeper water due to the larger top-end motion amplitude, compared with the fixed platform in shallow water. A coupled hydrodynamic force approach, involving the vortex-induced lift force along with the fluid drag force, is developed. The dynamic responses of the system including a floating top-end and a riser experiencing VIV are examined by means of finite element simulations. The effects of amplitude and frequency of top-end vessel sway on riser VIV are examined. Our numerical results show that the riser displacement becomes several times larger than the displacement for the case without top-end motion. Moreover, the nonlinear response amplification is observed, and the nonlinear amplification gets more pronounced as the number of mode order dropping, while the amplification factor just slightly changes with the increase of sway amplitude.

Coupled motion Dynamic response Risers Swaying Vortex induced vibration

ABSTRACTS 911

2015102439

Numerical simulation of wave in deck loading on offshore structures. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23847 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911512 Chen, Y., Wu, Y., Et al English

Extreme wave impacts on the decks of offshore structures with insufficient air gap may cause damage or even collapse with safety, economic, and pollution consequences. In this study, the impact loads on a fixed platform deck have been predicted numerically by employing a Navier-Stokes solver with the free-surface captured by the volume of fluid (VOF) method. 3D numerical simulations of wave-deck interactions for long-crested extreme waves were performed. The simulations successfully captured the evolution of impact loads and free surface of the waves during the interaction with the platform deck. A detailed parametric analysis of wave-deck interactions showed significant differences in loads under various situations and confirmed the large magnitudes of the loads to be expected during impact. The results presented include a solid box and a more realistic case of under-deck beams. These provide a useful benchmark for predicting wave loadings on platform decks and through this research programme the longer term aim is to establish improved guidelines for assessing the risk of existing structures.

Numerical models Offshore structures Platform decks Wave loads on structures

2015102440

Towing tank experiments on the vortex-induced vibrations of a flexible cylinder with wake interference. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23873 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911514 Huera-Huarte, F.J., Bangash, Z.A., Gonzalez, L.M. English

The paper describes recent results showing the dynamic response, excited by vortex shedding, of a long flexible cylinder subject to a stepped current immersed in the wake of another cylinder, placed upstream in tandem configuration. Experiments were conducted in a towing tank 80 m long with a cross-section of 4 × 2.5 m. A supporting structure was designed in order to provide support for a 3 m long cylinder with an external diameter of 16 mm. The cylinder was instrumented with strain gauges providing curvature measurements in the in-line and the cross-flow directions at 11 locations along its length. Tension and drag forces were also measured at both ends of the model. For these experiments, the upstream rigid cylinder was made stationary by fixing it at both ends, and it was located at different centre to centre distances. More than 200 runs were conducted, with its lower 65% length under the water free surface, connected to the structure by means of universal joints. The supporting structure allowed to configure different top end conditions and to apply different top tensions. Tests were conducted with speeds up to 1.4 m/s. The cylinder had a low flexural stiffness of 6.04 Nm2 and low mass ratio of 2.7. Fundamental natural frequencies were in the range from about 2.3 to 6.2 Hz, and the cylinder responded in modes up to the third cross-flow.

Cylindrical bodies Dynamic response Model tests Vortex induced vibration

912 ABSTRACTS

2015102441

Study on slamming pressure on the bottom of upper hull of semi-submersible type floater. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23905 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911515 Cheon, J.S., Jang, B.S., Et al English

Normally design bottom slamming pressure of semi-submersible type floater is determined in a simple way using a relative speed obtained from an air-gap analysis. However, there are few studies on a robust background on the estimation of the design pressure. In this study, to investigate the slamming pressure on the bottom of semi-submersible rig, a simplified deformable stiffened plate with 0° dead rise angle is simulated by using nonlinear FEM software, LS-DYNA which can take the influence of Fluid-Structure Interaction (FSI) into account. To simulate the slamming condition of semi-rig in a similar way, water hitting the structure with fixed boundary conditions is proposed. Various parametric studies are carried out to examine the effect of structural flexibility, coupling stiffness, mesh size, velocity, stiffener size, and air cushion effect. To further investigate the effect of horizontal velocity, the model is expanded and simulated with various horizontal water velocities. Pressure response on the plate by the coupling of fluid and structure is studied and the hydroelastic effect of each parameter is discussed.

Offshore structures Semisubmersibles Slamming

2015102442

A strong FSI coupling scheme to investigate the onset of resonance of cylinders in tandem arrangement. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4540-0. Volume 2: CFD and VIV. Paper No. OMAE2014-23715 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911518 Kara, M.C., Stoesser, T. English

This paper considers numerical simulations of two-

dimensional viscous flow past oscillating cylinders using an efficient, oscillation-free, Cartesian grid based Immersed Boundary Method (IBM). The direct forcing approach originally developed by Uhlmann for fixed and moving boundaries is employed. The IBM utilizes an improved smoothing technique for the discrete delta function and a solid-domain forcing strategy. A strong-coupling scheme is employed in which both, fluid and structure, are treated as linked components of a single dynamical system and all governing equations are iterated until convergence within the same time step. The accuracy, validity and efficiency of the utilized IBM are demonstrated by a series of validation cases including Vortex Induced Vibration (VIV) of an elastically mounted single cylinder and VIV assessment of a pair of cylinders in tandem arrangement. The method provides a good estimation of the single cylinder vortex lock in regime and fairly accurate predictions of the wake interference effect on the onset of resonance in flows involving multiple cylinders in an in-line arrangement.

Cylindrical bodies Fluid structure interaction Resonance Tandem arrangement

2015102443

Oblique water entry of a wedge with vortex shedding. 30th International Workshop on Water Waves and Floating Bodies; 12-15 April 2015; Bristol, UK. [4 p, 15 ref, 3 fig] http://www.iwwwfb.org/Abstracts/iwwwfb30/iwwwfb30_56.pdf Xu, G.D., Wu, G.X. English

The general problem of vortex shedding at a sharp corner of a marine structure has been receiving extensive attentions. Downie et al (1988) studied the vortex shedding of a rectangular barge in waves. Kristiansen & Faltinsen (2010) simulated the vortex shedding of a rectangular box in waves through BEM. The damping effects due to the shed vortices were accounted for properly. However, it seems that there is far less work in the context of water entry of a wedge, which is the focus of the present study. A Kutta condition for numerical simulation is imposed

ABSTRACTS 913

at the sharp edge. The pressure jump at the wedge apex is removed. Results for the free surface profile and pressure distribution are provided.

Vortex shedding Water entry Wedges

2015102444

Green water and wave impact on FPSOs in Santos Basin: challenges and prediction tools. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24087 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912102 Schiller, R.V., Pâkozdi, C., Et al English

Green water (water-on-deck) and subsequent wave impact is a strongly non-linear, random and complex phenomenon that represents an important factor to be considered in the design of moored vessels and vessels in transit. The Santos Basin, in southeast Brazil, is a new frontier for deep water oil production, where FPSO green water issues are expected to be more important. This paper investigates new green water challenges associated with the Santos Basin. The authors employ an engineering prediction tool, KINEMA, designed to predict wave-induced impact loads on FPSOs in steep irregular waves, and for use in early design load analysis. A sensitivity study is performed to arbitrary wave directions and preliminary results are presented from a case study that would be illustrating for the Santos Basin. Firstly, a comparison between numerical green water predictions and a set of earlier model test data for a Campos Basin case shows satisfactory agreement. A sensitivity study suggests that an empirical tuning factor, which is related to wave amplification and wave-structure interaction, should decrease with increasing wave heading. Then, a preliminary numerical investigation of the green water problem in Santos Basin wave conditions demonstrates that

although the wave impact from the largest waves (S-SW) may be avoided by heading the vessel towards S-SW, other wave directions have to be taken into consideration. The results presented confirm that multi-directional wave heading is a green water challenge in the Santos Basin. Further studies that address this problem in detail, in special variations in the wave-structure interactions due to wave heading, and for actual particular Santos Basin FPSO are recommended.

Deck wetness FPSOs Wave loads

2015102445

An experimental investigation of wave impact loads on a slender horizontal cylinder. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24182 [11 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912113 Haley, J.F., Swan, C., Gibson, R. English

This paper concerns the difficulties arising in the prediction of the impact loads associated with an extreme wave event. A new set of experimental observations are presented. These concern the impact loads arising on a slender horizontal cylinder located at varying elevations above the still water level. The experimental observations incorporate a wide range of wave forms. In each case, data is provided describing (i) the incident water surface profiles, (ii) the incident fluid velocities and (iii) the load components acting on the cylinder. Comparisons between the measured data and the classical impact load solutions confirm a number of important departures. In particular, it is shown that as the wave becomes very steep (approaching the breaking limit) the vector sum of the horizontal and vertical velocity components at the water surface may deviate significantly from the normal to the local water

914 ABSTRACTS

surface. In such cases it becomes unclear exactly what direction the impact force acts. The present data suggests that this is, in part, dependent on the rate of inundation of the body. Furthermore, the present results also show that if the direction of the force is correct modelled, the variations in the predicted loading (or slamming) coefficient are much reduced.

Cylindrical bodies Experimentation Impact loads Wave loads on structures

2015102446

Numerical simulation of short duration hydrodynamic impact. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-24323 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912117 Fu, T.C., O’Shea, T.T., Et al English

Numerical simulations of wedge impact experiments, undertaken by the Naval Surface Warfare Center, Carderock Division, NSWCCD, and more recently by the United States Naval Academy, USNA, Hydromechanics Laboratory, were performed using the computational fluid dynamics code Numerical Flow Analysis, NFA, to assess its capabilities in simulating the short duration hydrodynamic loading associated with free-surface impact. NSWCCD performed experiments using drop heights of 15.24 cm (6 in) and 25.4 cm (10 in), while the Naval Academy used drop heights of: 7.94, 12.7, 15.88, 25.4, 31.75, 38.1, and 50.8 cm (3.125, 5.0, 6.25, 10.0, 12.5, 15.0, and 20.0 in), measured from the keel of the wedge to the calm water surface. Simulations and comparisons were made at heights of 15.24 cm (6 in) and 25.4 cm (10 in) with the NSWCCD data, and 12.5 inches for the USNA data providing for a detailed examination of NFA’s ability to simulate and predict short duration hydrodynamic impacts.

Computational fluid dynamics Hydrodynamic loads Impact loads Wedges

3.5 AERODYNAMICS

2015102447

On aerodynamics of high speed boat sponsons. RINA Transactions - International Journal of Small Craft Technology, v 157 Part B1, January-June 2015 http://www.rina.org.uk/ijsct.html Grenestedt, J.L., Curran, K.P. English

Two different concepts for sponsons for high-speed manned or unmanned boats were conceived. Models were manufactured and wind tunnel tested. The objective of the first sponson concept was to have low aerodynamic drag, low aerodynamic lift, and low aerodynamic lift force gradient (lift as a function of angle of attack). This sponson would rely on hydrodynamic lift to support the entire boat. The objective of the second sponson concept was to provide very high aerodynamic lift, preferably so high that no hydrodynamic lift would be required for supporting the boat at speed. There would thus be little or no hydrodynamic drag. Another requirement for both sponson concepts was to aid in vehicle stability, which however is very different for the two sponsons.

Aerodynamics High speed vessels Sponsons Wind tunnel tests

2015102448

Effects Of Platform Pitching Motion On Floating Offshore Wind Turbine (FOWT) Rotor. OTC 2015, 46th Offshore Technology Conference; 4-7 May 2015; Houston, Texas, US. Paper 25962 [17 p] https://www.onepetro.org/conference-paper/OTC-25962-MS Sivalingam, K., Bahuguni, A., Et al English

The increasing demand for offshore wind energy is leading the industry to look for expansions into deep oceans. This development has compelled the industry to venture in to floating offshore installations for wind turbines. The floating installations lead to complex rotor motions in 6 degrees of freedom. The current work focusses on various aerodynamic effects on the turbine rotor due to coupled wind and wave forces. In this research work, the dynamic effects of the platform pitching motion on the rotor for OC3 phase IV case 5.1 are studied with rigid body

ABSTRACTS 915

assumption using high fidelity CFD (Computational Fluid Dynamics) commercial tool and semi empirical tool called FAST which is developed by NREL, USA. The hydrodynamic effects leading to the pitching motion of the turbine platform are extracted from the NREL FAST software. These pitching motions are coupled with the rotating blades to study transient flow behaviors using CFD tools. The results are compared with the standard BEM based methods to identify the discrepancies if any. Moreover, fine variation of rotor power/load due to dynamic pitching of the floating platform is also compared. The induction factors are extracted from the CFD results for every time step and are compared with those obtained with BEM based methods. Moreover, the application of CFD induction factor methods are introduced for cyclic load variations due to the rotor plane motions to check the validity of the BEM for FOWT application.

Aerodynamics Computational fluid dynamics Pitching Rotors Wind turbines

2015102449

Sail structure design and stability calculation for sail-assisted ships. Marine Engineering Frontiers, v 3, 2015, p 1 [13 p, 11 ref, 6 tab, 13 fig] http://www.seipub.org/MEF/paperInfo.aspx?ID=24165 Hu, Y., He, J., Et al English

This paper systematically introduces several aspects of sail-assisting technology. The paper firstly introduces sail type selection and experimental results of arc sail models. Thrust force coefficient, drifting force coefficient, lifting force coefficient, resistance coefficient and rotating torque coefficient of the sail model are discussed and optimal sail rotated angle is calculated in the paper. A control mechanism and the material of sail structure are designed for the sail operation of an ocean-going bulk carrier. Based on stability requirements of ocean-going ships, this paper proposes a stability criterion for sail-assisted ships

and suggests a calculation method of stability parameter for the requirements. Comments and recommendations are finally discussed for the further application of the sail onboard ship.

Heel (list) Sail assisted vessels Sails Stability Wind tunnel tests

4.1 STRUCTURAL RESPONSE

2015102450

Dynamic response of offshore jacket platform including foundation degradation under cyclic loadings. Ocean Engineering, v 100, 15 May 2015, pp 34-45 http://www.sciencedirect.com/science/article/pii/S0029801815000700 Mao, D., Zhong, C., Et al English

A 1/10 scale model is investigated to study the influence of the foundation degradation on the dynamic response of an offshore jacket platform. Experiments were conducted in multi-layer saturated soil under different water depth. A vibration exciter which amplitude and frequency could be changed was employed to simulate realistic loads. The model was scaled using dimensional analysis according to the artificial mass similarity principle and Buckingham π theorem. The horizontal dynamic response under the foundation degradation after varying cyclic loadings was studied. FE models were designed by means of the lumped parameter method or the equivalent pile technique to handle the pile-soil interaction in ABAQUS to analysis dynamic behaviour of the jacket platform. Experimental results show that the foundation degradation is related to the motion amplitude and the frequency of the piles. The degradation will result in the jacket natural frequency depressed, but it has little impact on the system damping. Comparison of the numerical and experimental results shows that applying the lumped parameter model with p-y curve PSI element to simulate soil-pile-upper structure interaction can

916 ABSTRACTS

obtain much higher accuracy than using the equivalent pile technique. Fair agreement between the experimental and theoretical results was obtained.

Cyclic loads Dynamic response Jacket structures Offshore platforms

2015102451

Investigation into the implications of increasing minimum manhole access requirements in marine structures. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 61 [10 p, 19 ref, 4 tab, 13 fig] https://www.crcpress.com/product/isbn/9781138027893 Eames, P., Hickson, H., Underwood, J.M. English

Enclosed spaces are one of the most dangerous aspects of maritime construction, operation and maintenance; life is endangered through the difficulties maintaining air quality and extracting injured personnel in the event of an accident. The number of incidents leading to serious injury and loss of life in enclosed spaces over the last 20 years is unacceptable, and although marine organisations are beginning to address the issue, access problems still remain. Research presented in this paper identifies that increasing minimum man-hole size would provide better access and rescue capability into enclosed spaces. The paper identifies means to increase standard manhole access sizes in ship double bottom spaces in new and legacy vessels, without compromising structural capability, in a bid to improve safety and survivability within enclosed spaces. Non-linear finite element analysis has been used to determine the influence of increased manhole access size on the ultimate collapse strength of stiffened steel plated structure typically found in large marine structures.

Enclosed spaces Safety Space requirements Structural analysis

2015102452

Simplified method for natural frequency analysis of stiffened panel. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 12 [8 p, 13 ref, 1 tab, 16 fig] https://www.crcpress.com/product/isbn/9781138027893 Avi, E., Laakso, A., Et al English

Vertical vibration of decks is typically the most significant mechanical vibration affecting passenger comfort in ships. In order to save modelling and calculation time, the global finite element model is often created using equivalent elements, where secondary stiffeners are incorporated into the plate or shell formulation in a way that it results in equivalent stiffness. However, the existing equivalent shell elements do not consider the local plate vibration between the stiffeners. This limitation causes the largest errors in areas of thin decks, where the natural frequencies of plates are closer to the global frequencies of the stiffened panel. Proposed approach corrects this error by combining the natural frequencies of the equivalent element with the local plate frequencies, which are pre-calculated using analytical formulae or sub-modelling technique. The combination is performed based on the assumption that the separate plates and stiffeners act as springs and masses in series. The method is applied for stiffened panels with pinned and clamped boundary conditions and good agreement with 3D fine mesh analysis is observed.

Resonant frequency Stiffened plates Theory

2015102453

Investigation of vibrational power flow patterns in damaged plate structures for damage localisation. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 13 [9 p, 10 ref, 4 tab, 20 fig] https://www.crcpress.com/product/isbn/9781138027893 Boonpratpai, P., Xiong, Y.P. English

Investigation of changes in vibrational power flow patterns in plate structures when damage appears is presented in this paper. The case studies are

ABSTRACTS 917

performed with thin rectangular plates which are widely used in marine applications. Damage on the plates is simulated using Finite Element Method (FEM) as a through-thickness crack. The high stress region is located at the vicinity of the crack tips. The power flow is generated by a unit harmonic point force placed at the specific locations on the plate. The patterns of the power flow are demonstrated in the form of vector fields. When the damage arises on the plate, the patterns of the power flow at the location close to the damage change significantly. These changes at the plates show that the location of the damage is effectively detected by the power flow. The detected location of the damage in this is presented visually using only the power flow vector plots.

Damage Rectangular plates Thin plates Vibration

2015102454

Influence of the sea action on the measured vibration levels in the comfort assessment of mega yachts. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 14 [6 p, 6 ref, 2 tab, 4 fig] https://www.crcpress.com/product/isbn/9781138027893 Brocco, E., Moro, L., Et al English

Understanding the methods to evaluate the comfort on board ships through direct measurements of the vibration levels is crucial for obtaining accurate results, and so a clarifying explanation of the methods required by the ISO 6954:1984 would be useful. The checking is performed using a Maximum Repetitive Value (MRV) that is not clearly defined, nor specified in which circumstances or for which dimension of the ship it should be used or not. Neither has an explanation been given to the use of a conversion factor that inherently represents time dependent vibration phenomena, modulation, which depends on the Sea State. The Crest Factor represents these modulations, and depends on the Sea State and ship dimensions. It is important to understand better the parameters that affect the Crest Factor to evaluate better the comfort on board ships. Some Classification Societies give guidelines on how to use

the ISO standard in question, but they do not always cover certain aspects that must be considered. In the paper, suggestions on how to use the standard are given, approaches from Classification Societies are analysed and a procedure to obtain MRA and the Crest Factor generated. Different influencing factors to the Conversion Factor and the MRA, such as time length and position of the measurement during testing and filter type, have also been analysed to obtain a more accurate value of the Crest Factor.

Comfort Motor yachts Sea state Vibration

2015102455

A computational framework for underwater shock response of marine structures. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 15 [8 p, 15 ref, 1 tab, 16 fig] https://www.crcpress.com/product/isbn/9781138027893 Diyaroglu, C., De Meo, D., Oterkus, E. English

Composite structures have extensive area of practice in engineering disciplines. One of the application areas is to use them under extreme loading conditions. However, understanding of their behaviour under shock loading is rather limited. As a result of this, current designs of composite structures are very conservative which significantly reduce the weight saving advantage. In order to improve understanding, experimental studies are essential but they can be prohibitively costly. On the other hand, computer simulations can be a good alternative. Hence, the main objective of this study is to investigate underwater shock response of marine composite structures by using a new theory called peridynamics. Numerical approach based on peridynamics is used to predict the failure modes in marine composite structures. The evaluated results are validated by comparing against the available data in literature which demonstrates the capability of peridynamics for such complex problems.

Composite materials Loads (forces) Shock Underwater

918 ABSTRACTS

2015102456

Numerical simulation of the dynamic behaviour of resilient mounts for marine diesel engines. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 17 [9 p, 19 ref, 1 tab, 14 fig] https://www.crcpress.com/product/isbn/9781138027893 Moro, L., Brocco, E., Et al English

On board ships, to avoid high levels of structure-borne noise due to marine four strokes diesel engines, the latter are usually resiliently mounted. In order to improve the effectiveness of the decoupling between the diesel engines and the ship structures, it is important to have available tools and numerical models that simulate the dynamic behaviour of the isolator system as well as of the receiving structures. In the paper, after an introduction to the basics for the characterization of passive resilient mounts in high frequency range, an FE non-linear dynamic model of the isolator is presented. Such model takes into account the dynamics of the cast-iron parts, the contact between the top and base casting with the rubber core and the non-linear behaviour of the constitutive law of rubber. A procedure to achieve the characteristics parameters of rubbers is presented. The simulations have been then validated by experimental tests.

Diesel engines Dynamic response Numerical models Resilient mountings

2015102457

Characteristic of low and middle frequency underwater noise of a catamaran. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 18 [7 p, 15 ref, 1 tab, 10 fig] https://www.crcpress.com/product/isbn/9781138027893 Pang, F.Z., Xue, Y.Z., Et al English

This paper examines the characteristic of low and middle frequency underwater noise of a catamaran. Based on acoustic-structure coupling method, the underwater noise radiations excited by both the mono-hull and double hulls are studied, respectively. Calculation method of underwater noise of twin-hull

craft is also discussed. Study shows that due to the existence of free surface and twin hulls of the craft, the underwater sound radiation varies especially in the near field. The sound directivity changes severely when standing wave appears between the region of twin hulls if the distance of bilateral hulls and sound wavelength satisfies certain conditions at certain frequency. However, if the standing wave effects do not occur between twin hulls the principle of linear superposition is approximately satisfied.

Catamarans Noise Underwater

2015102458

Simulation of the vibration characteristics of a propulsion system excited by hull deformations. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 19 [7 p, 16 ref, 7 tab, 9 fig] https://www.crcpress.com/product/isbn/9781138027893 Tian, Z., Yan, P., Et al English

This paper aims to investigate the vibration characteristics of the propulsion system subjected to hull deformation. Excited forces caused by severe sea waves have considerable effects on the hull deformation which could have great impact on the shaft propulsion system. On the contrary, the operation quality of ships and the durability of machines are threatened by the malfunctions of shaft propulsion system. This paper establishes a numerical model of the large ship propulsion-hull coupling system to analyse the vibration characteristics of the ship propulsion system subjected to hull deformation. In different sea conditions, the hull deformation was obtained as the exciting forces which are used on the coupling system. As a result, the vibration characteristics of the ship shaft are obtained. Based on the result, suggestions are proposed to ensure the normal operation of the propulsion system in different sea conditions.

Deformation Hulls Propulsion systems Vibration

ABSTRACTS 919

2015102459

A new approach to analyse the underwater vibration of double layer ribbed cylinder. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 20 [6 p, 12 ref, 3 tab, 9 fig] https://www.crcpress.com/product/isbn/9781138027893 Wang, F., Xiong, Y., Et al English

Analysing double layer ribbed cylinder’s underwater vibration is of great importance to the design and evaluation of vessels’ dynamic performance of operation and human comfort level. The two main traditional methods that are applied to solve this work are Flügge’s equations of motion and numerical method, such as FEM. Even though both methods have their own special advantages, complicated model developing process and comparative low accuracy (compared with data from real measurement) are their common drawbacks. In this paper, Neural Network is used to analyse the dynamic character of this double layer ribbed cylinder. Real measurement data are used to construct Neural Network, and after this Neural Network model is well built, comparison studies are processed between the vibration data of some positions of interest on the cylinder acquired from Neural Network and real test, respectively. The results show that Neural Network can be used to analyse the dynamic character of double layer ribbed cylinder and is of high accuracy and timesaving. The next step of this research will be concentrated on using more representative vibration data to develop Neural Network model.

Cylindrical shells Neural networks Underwater Vibration

2015102460

Effect of large openings without and with windows on the shear stiffness of side walls in passenger ships. Ships and Offshore Structures, v 10 n 3, June 2015, pp 256-271 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.912048#.VYfRe03JCUk Fricke, W., Gerlach, B. English

The side walls of passenger ships, ro/ro ferries and mega yachts are today characterised by large window

openings which affect the structural behaviour. The main effect is the decrease in shear stiffness within the plane. This well-known effect is important to be considered in structural analyses, such as longitudinal strength analyses where the effectiveness of the upper decks is reduced. However, the vibration behaviour of the hull girder is also affected. The paper reviews the state of the art with respect to consider this effect in finite element modelling. Furthermore, an analytical procedure for the derivation of the shear stiffness based on beam theory is presented. As clamped and bonded glass panes contribute to the stiffness particularly in the case of large opening ratios, the modelling of the elastic connection between wall and glass pane is also considered. In addition to hints for finite element modelling, which requires a relatively fine mesh of the connection, also the analytical procedure is extended to consider this effect by using the differential equation for a beam on elastic foundation. Finally, the transfer of the derived shear stiffness into a global finite element model of the ship is outlined, illustrated by a numerical example.

Openings Passenger ships Stiffness Structural response Windows

2015102461

Dynamic buckling of masts of large sail ships. Ships and Offshore Structures, v 10 n 3, June 2015, pp 290-301 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.887175#.VYfWSU3JCUk Gaiotti, M., Rizzo, C.M. English

The design of sail systems is a fascinating topic that naval architects have been facing since many centuries and nowadays is revived because of the increasing size of modern pleasure and racing yachts. It is hence surprising that empiricism largely drives mast and rigging design even at the present time. Actually, while structural dynamics is explicitly considered in current scantling design of hull structures, this is not usually the case for mast and rigging. However, numerical simulations can now be successfully applied to assess effects of load variations in time. Considering the governing limit states and the typical behaviour of a pre-tensioned slender structure, the dynamic buckling of the bottom panel of a typical large mast is evaluated in this paper, showing significant differences from the widely applied quasi-static approach. The obtained

920 ABSTRACTS

results provide a new perspective for the scantling assessment of sail systems, overcoming the current empirical and prescriptive approach proposed by rules of classification societies and international standards.

Buckling Finite element method Masts Sailing vessels

2015102462

Broadband cavitation excitation in ships. Ships and Offshore Structures, v 10 n 3, June 2015, pp 302-307 http://www.tandfonline.com/doi/full/10.1080/17445302.2014.942076#.VYfW503JCUk Carlton, J.S. English

The paper considers the origins and implications of propeller induced broadband excitation in ships. Attention is then given to the potential and shortcomings of the available methods by which the influence of broadband excitation from cavitating sources on the ship's structure can be evaluated. Finally, consideration is given to methods for the attenuation of broadband excitation.

Broadband Excitation Propeller cavitation Ship structures Structural response

2015102463

Numerical assessment of underwater noise radiated by a cruise ship. Ships and Offshore Structures, v 10 n 3, June 2015, pp 308-327 http://www.tandfonline.com/doi/full/10.1080/17445302.2013.790271 Salio, M.P. English

The present paper deals with a methodology for the prediction of propeller-induced acoustic pressures and associated ship response, having considered propellers as the main acoustic source onboard ships. Semi-empirical and numerical approaches have been coupled for the characterisation of the propeller and the determination of the radiated acoustic field, respectively. The boundary element method has been used for numerical analyses, and a commercial solver

has been adopted. The procedure has been applied to a cruise ship, and numerical results have been compared to the available experimental measurements. Other two different ships have been taken into account in order to test the methodology. Results show that the influence of the structural finite element mesh of the ship on the computation is comparable to acoustic characterisation of the propeller. Furthermore, it is found that the reliability of semi-empirical methods is not completely satisfactory; nevertheless, they are currently used at an early design stage as common practice.

Boundary element method Cruise ships Finite element method Propeller noise Underwater acoustics

2015102464

Consequences of using the plane stress assumption for damage calculations in crash analyses. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-23946 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911663 Walters, C.L., Voormeeren, L.O. English

Simulation of failure in plate materials (represented as shell elements) is critical for the correct determination of crash performance of ships and offshore structures. This need has traditionally been filled with failure loci that give the failure strain in terms of stress triaxiality. In recent years, a third dimension (Lode parameter) has been introduced in the form of the Modified Mohr Coulomb failure criterion and Lode parameter adjusted Gurson-type models. This development introduces ambiguity for shell structures, in which only two dimensions are represented. The typical way of addressing this is to assume that shell structures fail in plane stress, thus reducing the problem back to 2-D. However, the assumption of plane stress is violated as soon as necking begins, causing different stress triaxialities and Lode parameters than would be expected from the planar case. More importantly, the inhomogenous

ABSTRACTS 921

necked region is then homogenized over the entire shell element. In this paper, the consequences of the through-thickness plane stress assumption are assessed through a finite element model of a plate that is subjected to a far-field stress.

Damage Shell structures Stresses

2015102465

Stability analysis and experiment of large-scale spherical models built by high strength steel. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24056 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911666 Du, Q., Cui, W. English

The spherical shell is a typical form of revolution shells which are used widely in engineering especially as underwater pressure hull. To disclose structural characteristics of the whole spherical shell with some initial imperfections and residual stresses, both material nonlinear and geometric nonlinear Finite Element Analysis (FEA) has been carried out in this paper. In the FE analysis, the elastic-plasticity stress-strain relations have been adopted and the initial deflection of spherical shell caused in manufacture was also taken into account in creating model. It is also shown that the nonlinear structural characteristics of the spherical shell vary from its different dimension parameters for initial imperfection. Compared with the exiting different rule’s methods, nonlinear FEM may exactly show sphere’s stability varying by initial imperfections. Then two groups of experiments of four spherical models, made by a high strength steel and with two kinds of same main sizes but with different initial deflection on them for manufacture, have been finished in model pressure tests. The experiment has

been analysed by comparing in different method while these results eventually indicate that the buckling stability of a spherical shell model varies by its initial imperfection and such materials sphere critical load could not be accounted for by current rules except nonlinear FEM or modified theoretical elastic-plasticity analysis method. Therefore it is essential to obtain the new analysis and design method for spherical shell made by high strength steel used to deep-sea vehicle or other ocean engineering.

Finite element method High strength steel Shell structures Structural response

2015102466

Residual compressive strength of dented FPSO side shell panel. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24059 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911667 Amaral Amante, D. do, Chujutalli, J.A., Estefen, S.F. English

This paper presents a non-linear finite element study to obtain the ultimate compressive strength of dented FPSO side stiffened panels. The finite element program ABAQUS was used to perform numerical analysis. The analysis is carried out in two steps. First the supply collision damage is imposed using the ABAQUS explicit code program. After the indentation, a compressive load is applied and then the panel residual compressive strength is obtained. A parametric study was accomplished to evaluate the influence of the dent depth on the stiffened panel strength. Damages occurring on the stiffener and between the stiffeners are compared.

Compressive strength Damage Finite element method FPSOs Shell structures

922 ABSTRACTS

2015102467

Numerical evaluation of energy absorption in ship-offshore fixed platform collisions. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24118 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911670 Travanca, J., Hao, H. English

Among the structures built offshore, the fixed type constitutes the majority. The consequent diversity of plausible collision scenarios involving offshore platforms and passing ships must therefore consider aspects such as different ship size, different impact energy or different impact locations. For high energy collisions, large deformations are expected on both the platform and ship structures. It is expected that part of the energy absorption in the platform is confined to localized zones where plastic deformations take place, although the elastic strain energy may also be significant. For such impact problems, the amounts of strain energy in each structure are mainly dependent on the relative stiffness of the structures. By taking different ship and platform configurations as well as different contact points between the two bodies, different relative stiffness of the two structures can be tested in order to provide a clearer understanding of the dissipation of strain energy. The possible plastic deformation mechanisms are analysed and simplified approaches are considered for prediction in comparison with the numerical results carried out by finite element analysis. Based on the results, some evaluations are made with respect to the code of practice in offshore platform design against ship impact.

Energy absorption Platform rammings

2015102468

A case study of the influence on crashworthiness from the implementation of ice strengthening. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24127 [9 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911671 Aga, H.L., Leira, B.J., Et al English

This paper presents a study of the influence from ice strengthening on the crashworthiness with regards to placement of LNG fuel tanks. First a brief introduction to the ship collision research as well as an assessment of the state of the art regarding nonlinear finite element analysis for use in ship collision analysis is given. Secondly the implications from the introduction of LNG fuel tanks on ships in context of collision safety are discussed. Thirdly how to quantify and compare energy absorption for different ship designs is discussed. This is followed by the presentation of a study regarding the horizontal placement of LNG fuel tanks. The study starts with presenting the variables chosen and the models made for the analysis. Energy versus indentation curves are presented for three different designs, where a standard cargo carrier is compared with two different design solutions where the cargo carrier is equipped with either vertical or longitudinal ice strengthening. It is concluded that in this case the benefit in terms of reduction of the minimum distance from the outer skin to the LNG fuel tank, as given in the current rules, is around 39%.

Collision resistance Energy absorption Fuel tanks Ice strengthening

ABSTRACTS 923

2015102469

An enhanced 1-way coupling method to predict elastic global hull girder loads. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24199 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911675 Ley, J., El Moctar, O. English

This paper introduces a numerical method to predict global hull girder loads of sea-going vessels, taking into account the structural elasticity. A field method based on a Finite Volume discretisation is applied to simulate the nonlinear rigid ship motions and provides the external loads at the hull surface. The structural response is computed in a full transient 3D-Finite-Element Analysis. The lowest global structural mode shapes and Eigen frequencies are covered by the 3D-FE model. The mapping between the Finite Volume mesh and Finite Element grid is performed by the Mesh-Based Code Coupling Interface (MpCCI). As long as only global vertical bending modes are considered, simplified beam models may sufficiently cover the structural response. However, the use of the 3D-FE model is motivated by the prediction of the global torsional and local loads that are influenced by hydroelastic effects. A 1-way coupling method is applied. To account for hydromass effects, the Finite-Element model is enhanced by acoustic elements. Acoustic wave equations are solved to simulate the sound wave propagation in water and to obtain realistic Eigen frequencies of the wetted hull. Structural and hydrodynamic damping is controlled by the Rayleigh-Damping method. Simulations are performed for an ultra large container vessel sailing in regular head waves. The computed time histories of the vertical bending moment are compared with experimental data and with numerical simulations using a strong 2-way coupling simulation that employs a Finite-Element Timoshenko-Beam.

Elastic properties Hull girders Loads (forces) Stresses

2015102470

Shock response of ship section to underwater explosion with the cavitation effect. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4551-6. Volume 8B: Ocean Engineering. Paper No. OMAE2014-23916 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912081 Chen, Y-y., Yao, X., Et al English

Besides the shock wave load and the gas bubble pulse load, cavitation effect has a significant influence on the ships subjected to underwater explosion. The goal of this research is to investigate the cavitation effect on the response of ship section using acoustic-structural arithmetic. Comparison between the structure response considering the cavitation effect and not, the formation mechanism of cavitation zone are discussed. The simulation results show acoustic-structural arithmetic can be used to numerical simulate the dynamic response of simple structure and ship section subjected to underwater explosion with the consideration of cavitation effect. And it also can be used to capture the cavitation in the water. Meanwhile, the simulation results show that cavitation zone generated by underwater explosion is very large, and the reloading effect is obvious with the consideration of cavitation effect. The vibration of the ship structure is more severe with the reloading, and thus more serious damage occurs as the result of the prolonged loading time.

Cavitation Explosions Ship structures Shock Structural response

2015102471

Residual ultimate strength of box girders with variable cracks. TransNav, v 9 n 2, June 2015, p 193 [6 p, 15 ref, 9 fig] http://www.transnav.eu/Article_Residual_Ultimate_Strength_Ao,34,572.html Ao, L., Wang, D. English

The aim of this study is to investigate the residual ultimate strength characteristics of box girders with variable cracks under torsional loading. A series of

924 ABSTRACTS

finite element models are established by changing the crack length and crack angle using a commercial FEA program, ABAQUS. The cracks are located at the centre and torques are applied on both ends of the box beam. Different aspect ratios are considered to evaluate the effects of cracks on box beams for various widths and lengths of panels in the middle yielding region. The accuracy of the nonlinear FEA results is verified by a comparison with previous predicted formulas. Based on the FEA results, the relationship between the residual ultimate strength and crack parameters can be indicated in a function with period of in the form of Fourier series.

Box shapes Cracks Girders Torsion Ultimate strength

2015102472

Springing effect on the fatigue life of an 8000TEU container ship. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 32 [8 p, 7 ref, 9 tab, 15 fig] https://www.crcpress.com/product/isbn/9781138027893 Liao, P.-K., Lee, Y.-J., Et al English

This study investigated the springing effect on the fatigue life of an 8000TEU container ship by performing hydro-elastic analyses. The hydro-structure computations consist in evaluating the hydrodynamic loads and transferring them directly to the finite element model of the ship structure. The quasistatic and dynamic responses of the structure can then be evaluated and the fatigue life assessed through spectral analysis. This study evaluated the fatigue life at two hot spot locations and considered several wave environments at two ship speeds. In addition, this study evaluated the effect on the fatigue of various natural modes of hull girder vibration. The results showed that because of the springing effect, the ship fatigue life decreased by 16% to 46%

depending on the hot spots locations and the operating conditions. Therefore, the effect of the springing phenomenon on the fatigue life is non-negligible in large container vessels design and should be carefully evaluated.

Containerships Fatigue life Hydroelasticity Springing

2015102473

Fatigue reliability assessment for brace-column details in a semi-submersible hull. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24228 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911677 Schmidt, D., Manuel, L., Et al English

Semi-submersible floating platforms used in the offshore deepwater environment have hull structures that are comprised of vertical cylinders (columns) connected by braces, pontoons, etc. Several of the connections between these various members are susceptible to fatigue damage. In fatigue damage assessment or fatigue reliability analysis, a global structural response analysis is typically carried out using a finite element model where internal forces or stresses in the various members are evaluated for specified sea states of interest at the site. Of specific interest in this study is the fatigue reliability analysis of brace-column connection details in a semi-submersible hull unit for selected Brazilian environmental conditions. Stress concentration factors for the selected critical hot spots are applied to the nominal component stresses due to axial forces and biaxial bending. The hot-spot stress response spectra are used with various spectral methods - referred to as Rayleigh, Modified Rayleigh (with bandwidth correction), and Dirlik - to estimate fatigue damage using Miner’s rule. Uncertainty estimates in

ABSTRACTS 925

fatigue damage rates and life based on the various methodologies are discussed and critical sea states are identified, highlighting dynamic and quasi-static influences on the predicted fatigue.

Columns (supports) Fatigue (materials) Offshore structures Semisubmersibles Structural reliability

2015102474

The small-scale distortion model design method for ultimate strength test of hull girder. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24361 [5 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911682 Li, C., Ren, H., Et al English

The objective of this paper is to develop a design method of small-scale distortion model for ultimate bearing capacity test. The ultimate moment is an important index of ship girder strength. Experimental analyses are regarded as the most straightforward and effective methods to predict ultimate moment of hull girder, especially full-scale and/or large-scale model testing. However, large-scale model test not only requires high loading capacity of test device, but it also costs a lot of human and material resources. Based on the similarity theory and failure mechanism of hull girder under bending, a small-scale distortion model design method is presented in this paper. In which, the transverse section is divided into several parts, such as main deck, middle deck, bottom and so on. Then, two similar criterions are required to follow. There are section modulus of each part and critical stress of main stiffened plats. The similar section modulus ensures a similar stress distribution of transverse section between model and real structures under bending; the similar critical stress

ensures the same failure modes of stiffened plates. Based on this method, a real vessel is taken as example to design its small-scale (1/25 scale) distortion model. The simulating results indicate that this model design method is precise and reliable.

Bearing capacity Distortion Hull girders Ultimate strength

2015102475

Structural integrity assessment of independent type ‘C’ LNG carriers. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24439 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911684 Wang, B., Shinb, Y-S., Wang, X. English

The objective of this paper is to present a complete procedure for strength evaluation of independent Type ‘C’ LNG carriers. This strength evaluation procedure includes two main parts, global finite element (FE) analysis mainly for hull structure evaluation and detailed FE analysis for tank and saddle supporting structures. A global FE model with three tanks including hull, tank and saddle supporting structures is used for structural analysis. Static and dynamic loads are applied to the global FE model as design load cases for the total strength assessment (TSA). FE analyses on the three tanks model have been performed and verified by the developed acceptance criteria to evaluate the safety adequacy of yielding, buckling, and fatigue of the hull and supporting structures. Additionally, a detailed FE model for a pressurized tank and its saddle supports is made, which consists of major components including tank shell, ring stiffeners, longitudinal central bulkhead, and saddle supports. An FE stress analysis of the pressurized bi-lobe tank with saddle supports considering the hull deflection effect has been carried out under internal pressure, dynamic loads due to ship motion, and thermal loads. Finally, an FE buckling

926 ABSTRACTS

analysis of the bi-lobe tank has been carried out under external pressure following gas carrier (IGC) code requirements. Meanwhile, acceptance criteria are developed for yielding and buckling strength evaluation of pressurized bi-lobe tanks according to the ASME Boiler and Pressure Vessel (BPV) Code. An independent Type ‘C’ bi-lobe LNG vessel has been utilized to implement the presented evaluation procedure. Finally, a complete procedure for evaluating the structural strength of cargo tank structures, supporting members and hull structures has been developed for an independent Type ‘C’ LNG carrier.

Finite element method LNG carriers Structural strength

2015102476

Non-conservative consequences of “conservative” assumptions in ship-platform collision analysis. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24457 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911686 Storheim, M., Amdahl, J. English

When designing offshore structures it is normally required to withstand a ship impact of a given magnitude without having progressive collapse of the structure. A common assumption when verifying a structure’s crashworthiness is to consider impact from a rigid vessel. This is argued to be a conservative assumption, as the struck structure will have to dissipate all energy. At a given time instant during a real collision, the weakest body will deform. Thus, if the actual strength of the platform is greater than that of the striking vessel, the rigid assumption will be wrong. For impact between a platform and a supply vessel, contact can occur for both the stem (forecastle structure) and the bulb simultaneously. Analyses show that there is a large difference between the strength of the stem and the bulb structure for conventional supply vessels, both in terms of total force and more importantly the pressure exerted to the struck structure. Thus, while the bulb might be stronger than the struck object, the stem is normally crushed. If a completely rigid vessel is assumed, the strain energy dissipation in the struck structure in way of the stem would be highly over-predicted, thereby

lowering the estimate of the damage caused by the bulb. This paper investigates the consequences of the rigid assumption by nonlinear finite element analysis. A modern large supply vessel design is checked. The differences between a rigid and a deformable vessel are highlighted, and non-conservative results identified.

Collision resistance Platform rammings

2015102477

Collapse analysis of offshore platforms using constrained new waves. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24549 [10 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911690 Kimiaei, M., Edgarth, D.W. English

Traditionally regular deterministic wave theories are employed to estimate wave loads on offshore platforms but they cannot capture random nature of the sea states. Randomly generated sea surfaces will lead to most accurate results for structural responses due to waves but they are usually based on long duration simulations and hence need excessive computational efforts. Constrained NewWaves (CNWs), with significantly shorter computational time, have recently been used successfully for estimating of structural response of offshore platforms due to waves. For extreme waves, as long as there is no indication of major structural nonlinearity in the system, they have shown reasonably accurate results as an alternative for long duration randomly generated sea surfaces. This paper is concerned with using CNWs in collapse analysis of offshore platforms under extreme waves where large geometrical and material nonlinearities are expected. It shows how the plastic level of the response, total duration of the loading, the loading pattern and dynamic characteristics of the platform can influence the extreme response and collapse rates of the offshore platforms.

Collapse Extreme waves Offshore platforms Wave loads on structures

ABSTRACTS 927

2015102478

Ship impact behaviour on jacket type offshore wind turbine foundation. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24578 [7 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911692 Zhang, J., Gao, D., Et al English

A jacket is an ideal supporting structure for large 4 to 6 MW offshore wind turbine (OWT) in deep sea. However, due to the harsh marine environment, and the fact that offshore wind farms are mostly located near a busy waterway, it is inevitable that ships crash into offshore wind power structures. Sometimes, collision accidents may result in severe damage in the support structure. To study the collision behaviour of a jacket offshore structure, dynamic characteristics of the jacket OWT foundation is analysed in this paper, based on ADINA explicit dynamic analysis method, considering different ship speeds, impact locations and joint thickness. Based on the numerical results, the joints are reinforced in special location to meet requirements. Structural performances of jacket type OWT foundation under ship impact are studied.

Collision resistance Dynamic analysis Foundations Jacket structures Wind turbines

2015102479

Low frequency vibration control of the offshore fixed platforms by using tuned liquid column damper. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4543-1. Volume 4B: Structures, Safety and Reliability. Paper No. OMAE2014-24635 [6 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1911702 Lee, C.H., Kim, H.W., Joo, W.H. English

Offshore fixed platforms are confronted with greater wind and wave forces as their installation site moves toward the deep sea, so it is definitely necessary to

reduce the low frequency vibration of structures for the safety and comfort of crews. The dynamic dampers are generally used to reduce vibration of structures. Especially, the tuned liquid column damper (TLCD) has been applied to reduce the low frequency vibration of onshore tall buildings. In this paper, the design procedure of TLCD is proposed to control the low frequency vibration of fixed platforms through the simulation and experiment with a small-scale model. The vibration control target is the surge motion of fixed platforms and the major design variables of TLCD are mass and damping ratios. The optimised design variables of TLCD are determined from the calculation of the amplification factor. In the experiment, the effects of mass and damping ratios are considered by changing the breadth of column, the opening ratio and number of the orifices. The results of experiment are found to well agree with the simulation. The 83% of structure vibration level can be reduced by applying the optimised TLCD.

Offshore platforms Vibration damping

2015102480

Ice model tests with a compliant cylindrical structure to investigate ice-induced vibrations. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4556-1. Volume 10: Polar and Arctic Science and Technology. Paper No. OMAE2014-24011 [8 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912287 Ziemer, G., Evers, K-U. English

A compliant cylindrical structure has been built and tested in a series of model tests in ice. The structure’s stiffness in ice plane is higher in ice-drift direction than crosswise, enabling the model to vibrate in different oscillation patterns. In total, 4 ice sheets have been used to perform tests in different ice thickness, covering a wide range of ice drift velocities between 0.005 and 0.15 m/s in model scale. Several events of ice-induced vibrations were observed throughout the test campaign. Oscillations are found to reach different types of beginning steady-state, mainly depending on ice drift velocity and ice thickness. Dynamic amplification of structural response in ice plane as well as ratio of static and dynamic forces is highly dependent on the type of vibration. While the dynamic amplification is highest when the ice load’s frequency equals the first natural

928 ABSTRACTS

frequency of the structure, the highest dynamic forces occur when the crushing frequency is an integer fraction of the natural frequency. The paper describes the design of the test set-up, instrumentation and calibration, performance and analysis of conducted tests, and general findings.

Cylindrical bodies Ice Model tests Vibration

2015102481

Study of ship-ice collision on ice breaker ARAON. OMAE 2014, 33rd International Conference on Ocean, Offshore and Arctic Engineering; 8-13 June 2014; San Francisco, US. Organised by ASME, New York, US; ISBN 978-0-7918-4556-1. Volume 10: Polar and Arctic Science and Technology. Paper No. OMAE2014-24420 [5 p] http://proceedings.asmedigitalcollection.asme.org/proceeding.aspx?articleID=1912301 Kim, S., Nho, I., Et al English

The interaction between a ship and sea ice is a complex process depending on the ice properties, the ice geometry and the relative velocity between the ship and the ice. The effect of important parameters such as ship speed and ice thickness on the impact force is studied by means of finite element model. Idealized ice element types are applied to finite element model in order to survey the impact force and the structural response of icebreaker ARAON subjected to sea ices. Interaction behaviours obtained by finite element model considering the varying parameters are also discussed to compare the numerical results with the design data of ARAON.

Ice forces Icebreakers Interactions Sea ice Structural response

2015102482

Non-accidental structural failures of large size tankers. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [5 p] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=0d9b879a-bad7-4ef3-a147-c3c13d11f4da Eliopoulou, E., Farmakis, E., Papanikolaou, A. English

The paper presents the findings of a comprehensive statistical analysis of the Non Accidental Structural Failures (NASF) pertaining to large crude oil tankers with deadweight over 60,000 tonnes. Relevant raw data have been deduced mainly from the IHS casualty data-base for the post 1990 period. Since the particular accident category, which mainly refers to deficiencies, including the fatigue of ship’s structure, is strongly related to ship’s structural design, thus to basic hull type of tanker design, only double hull ships were studied, whereas results of non-double hull ships are exception-ally presented. Basic event characteristics are presented, such as the degree of incidents’ severity, event location and ship operating condition at the time of incident, loss of watertight integrity, weather impact, loss of life/injury, oil spill occurrence and the final outcome of incidents. Some information about the origin of the building shipyards and the operating flags are also presented and discussed. This work complements earlier published work of the authors on large tankers casualty analysis and safety, where the focus was more on navigational type of accidents.

Large tankers Statistical analysis Structural failure

ABSTRACTS 929

4.2 PROPERTIES OF MATERIALS

2015102483

Corrosion fatigue crack growth in offshore wind monopole steel HAZ material. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 24 [6 p, 15 ref, 8 fig] https://www.crcpress.com/product/isbn/9781138027893 Adedpipe, O., Brennan, F., Kolios, A. English

Offshore wind is an emerging clean and environmentally friendly renewable energy source that has developed rapidly to meet the European Union 2020 renewable energy targets. Monopiles are the most commonly used offshore wind turbine support structures and are exposed to harsh marine environments similar to those experienced by structures for oil and gas applications. However, they have significantly different design requirements due to operational loads envelope and structural stiffness. Therefore the knowledge of corrosion assisted fatigue damage in monopile support structures is of a vital importance to ensure economical and safe operation of the structures in service. In this paper, results are presented on fatigue crack growth of HAZ (Heat Affected Zone) specimens made of S355 J2+N steel in air and in free corrosion conditions. The fatigue crack response in the HAZ materials are compared to that of the base material and significant difference in the test results is discussed.

Corrosion fatigue Crack propagation Fatigue cracks Heat affected zone Steel structures

2015102484

Improvements in fatigue strength assessment of marine propellers. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 25 [11 p, 13 ref, 12 tab, 15 fig] https://www.crcpress.com/product/isbn/9781138027893 Bertoglio, C., Gaggero, S., Et al English

The importance of considering fatigue phenomena in

propeller design is analysed by proposing a reviewed procedure for propeller blade fatigue assessment, already presented in a previous work. According to the results of fatigue tests collected from open literature and to fatigue design methodologies for propellers operating in ice, new corrections and coefficients are defined and introduced in the fatigue assessment. The reviewed procedure is applied to two different test cases. The analysis of the results underlines the importance of a more detailed and direct approach to propeller structural design which, at least in particular cases, could lead to benefits in the propeller performances.

Bronzes Fatigue strength Propellers

2015102485

Fatigue crack growth performance of laser hybrid and arc welds of AH36 naval steels. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 26 [7 p, 8 ref, 3 tab, 15 fig] https://www.crcpress.com/product/isbn/9781138027893 Chatzidouros, E.V., Tsiourva, T., Et al English

Although the laser hybrid process has been introduced for quite a while in mainstream shipbuilding, there are scarce data regarding comparison between Fatigue Crack Growth (FCG) of arc and laser hybrid welding of similar steels. In this work the fatigue crack growth performance of AH36 steel welds, using arc and laser hybrid technique are evaluated and compared. Following the BS 7448-2 standard, notched and pre-cracked bend specimens, with the notch and crack residing in the middle of the weld, are tested in order to ascertain the FCG performance. It is found that the FCG performance of the laser hybrid welded specimens is superior to the arc welded ones, exhibiting lower da/dN in similar ΔΚs. Furthermore the microstructures of arc and laser hybrid welds along with the hardness profiles on the welds are used in order to arrive in useful conclusions regarding the FCG performance of the two welding methods.

Arc welding Fatigue cracks Laser welding Steel Welded joints

930 ABSTRACTS

2015102486

Consideration of stress gradient effects for complex structures in local fatigue approaches. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 28 [9 p, 25 ref, 4 tab, 8 fig] https://www.crcpress.com/product/isbn/9781138027893 Fischer, C., Fricke, W. English

The assessment of the fatigue strength by means of local approaches is very conservative compared with experiments of complex plated structures connected by welded joints. Here, relatively long crack propagation phases were observed. At first, this paper deals with numerical crack propagation simulations which were performed for different geometrical variants. The analyses aim to identify why the life extends if the number of intersected plates increases. In conclusion, the stress gradient over the plate thickness, the apparent plate thickness and the load-carrying grade of the weld slows down the crack propagation rate. Secondly, a correction method is proposed how these effects can be considered in the structural hot-spot stress or effective notch stress approaches. Different reduction factors are introduced which were derived from crack propagation analyses. The factors reduce the local reference stress of the applied approach. Finally, the method is applied to an example of a complex structure, and the computed fatigue strength is compared with test results.

Crack propagation Fatigue life Fatigue strength Ship structures Welded joints

2015102487

Fatigue assessment of joints at bulb profiles by local approaches. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 29 [9 p, 26 ref, 4 tab, 13 fig] https://www.crcpress.com/product/isbn/9781138027893 Fischer, C., Fricke, W., Rizzo, C.M. English

This paper summarizes the research work carried out in Germany and in Italy about the fatigue strength of joints between bulb plate profiles, typically applied

by the shipbuilding industry. Fatigue tests of different joint configurations were carried out and several local approaches were applied. The paper focuses on the fatigue assessment approaches based on the notch stress intensity factor, which assume that fatigue is governed by the singular stress field at notch tips. Two approaches, referring to either the local strain energy density or to the peak stress value, are presented and applied. Additionally, a sensitivity investigation regarding the geometry of the weld seam of butt joints was performed on the basis of strain energy density approach. Comparisons with test data and with assessments of other common approaches offer a critical review about where the pros and the limitations of each approach are.

Butt welds Fatigue strength Fatigue tests Stiffeners

2015102488

Fatigue life improvement of laser-welded web-core steel sandwich panels using filling materials. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 30 [7 p, 25 ref, 2 tab, 10 fig] https://www.crcpress.com/product/isbn/9781138027893 Frank, D., Romanoff, J., Remes, H. English

Steel sandwich panels are being investigated for several decades because of their favourable strength-to-weight and stiffness-to-weight ratios. However, their application in shipbuilding is still limited since their response under fatigue loading is insufficiently explored. Recent literature demonstrated that the J-integral is convenient fatigue strength parameter for assessment of web-core steel sandwich panels. This paper uses the J-integral concept in the assessment of web-core panels filled with polyurethane (PUR) and Divinycell® foams of different densities. It is well known that adding a filling material increases flexural stiffness of the panel. The results obtained here show how low-density foam already significantly increases the fatigue life of a panel subjected to lateral fatigue

ABSTRACTS 931

loading. The paper outlines the possibility of multiplying panel’s fatigue life several times, while negligibly increasing its mass.

Fatigue life Laser welding Sandwich panels

2015102489

A full-scale fatigue test on longitudinal-through-bulkhead detail by using equivalent angle bar. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 31 [8 p, 12 ref, 6 tab, 14 fig] https://www.crcpress.com/product/isbn/9781138027893 Yi, Q., Yue, Y., Et al English

Fatigue experiment on full-scale details is significant for ship structural fatigue life evaluation. However, the flat bulb for full-scale test model is usually not available at laboratory, especially at the ship’s design stage. This paper proposes to use an equivalent angle bar with uniform thickness which is cold-formed from flat plates to take place the flat bulb in the full-scale fatigue test model. Firstly, Finite Element (FE) analysis is performed on the model with such equivalent angle bar to verify that the Hotspot Stress (HSS) distribution around its weld joint is similar as the real ship detail. For comparison, a non-uniform angle bar suggested by some classification rules is also investigated for its HSS distribution. Then, a bilge Longitudinal-through-bulkhead at a river-to-sea ship structure detail is chosen as the test model. The fatigue test on such full-scale model under biaxial load is carried out. And the HSS distribution and fatigue crack propagation are demonstrated. At last, the fatigue life of this ship structure detail with flat bulbs is calculated based on classification rules. By comparison of the rule-based result and the fatigue test result, the proposed test model fabricated from the equivalent angle bar can give good prediction of the fatigue life of structure details.

Angle bars Bulkheads Fatigue life Fatigue tests

2015102490

Mechanical characterization of yachts and pleasure crafts fillers. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 71 [9 p, 5 ref, 4 tab, 15 fig] https://www.crcpress.com/product/isbn/9781138027893 Nebbia, G., Rizzo, C.M., Et al English

This paper describes an experimental campaign specifically intended for the mechanical characterization of fillers. Fillers are two-component particulate composites, characterized by type, size and content of glass microsphere, randomly embedded in an epoxy matrix. Hull and superstructure of yachts are covered by filler to mould the surfaces. To obtain painted shiny surfaces, the filler should be perfectly levelled, faired and smoothed. Differently to the works presented in open literature, this paper focuses on the macro-mechanics properties regardless the fillers’ internal mechanic. Two types of tests were designed and conducted on six different fillers: a compression strength test on simple filler specimens and a three point bending test on specimens made by filler applied onto a steel substrate. Load-displacement curves of tested fillers were acquired providing the basis for the characterization of strength and stiffness. Results are repeatable and consistent and comparisons among different fillers are presented.

Composite materials Experimentation Fillers Mechanical properties

2015102491

Fatigue strength of welded extra high-strength and thin steel plates. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 35 [7 p, 12 ref, 6 tab, 14 fig] https://www.crcpress.com/product/isbn/9781138027893 Remes, H., Peltonen, M., Et al English

Weight reduction of structures is possible using thinner plates, i.e. with thickness between 3 and 4 mm, and high-strength steels. However, current design rules do not support their utilization in ship

932 ABSTRACTS

structures. This paper investigates the fatigue strength of welded Extra High-Strength (EHS) and thin plate structures. Fatigue tests were carried out for butt welded specimens and the results were analysed using the structural stress approach, which considerers the actual geometry of the specimens. The results show that the present nominal stress design S-N curve FAT80 with the slope value of three is applicable to thin welded EHS plates, but it is somewhat conservative especially at high cycle regime. The fatigue test results in terms of structural hot-spot stress are significantly above the design S-N curve FAT100. For the welded thin EHS plates, the slope value of five shows better agreement when the structural hot-spot stress approach is applied.

Fatigue strength Fatigue tests High strength steel Plates Thin plates

4.3 CORROSION AND FOULING

2015102492

Keeping your guard up. The Naval Architect, June 2015, p 39 [6 p, 10 ref, 1 tab, 12 fig] http://www.rina.org.uk/tna.html Sørensen, K.F., Hillerup, D., Et al English

HEMPGUARD X5 and X7 are the first antifouling products on the market to utilise the patented ActiGuard technology. This paper explains how the technology works. The biocide release-rate in ActiGuard is independent of sailing speed unlike traditional coatings. This means that ActiGuard-based coatings deliver extraordinary antifouling performance under idle conditions, but does not waste unnecessary amounts of biocide while the ship is sailing, thereby extending its active lifetime.

Antifouling coatings Silicons

2015102493

The appliance of science. The Naval Architect, June 2015, p 45 [3 p, 6 fig] http://www.rina.org.uk/tna.html No author given English

Water ballast tank coatings are fundamental to the structural integrity of ships. It is, therefore, essential that they are applied correctly. Nippon Paint Marine has developed an innovative coating that enables a yard to maximise efficiency and gives the shipowner confidence that their tanks receive the optimum coating.

Ballast tanks Tank coatings

5 NAVAL VESSELS AND DEFENCE TECHNOLOGY

2015102494

Human-system integration to achieve through life cost reduction. Warship 2015: Future Surface Vessels, International Conference; 10-11 June 2015; Bath, UK. Organised by RINA, London, UK. [7 p, 14 ref, 1 fig] http://www.rina.org.uk/publications.html Greenbank, C., Richards, D., Harmer, S. English

As modern Navies balance the trade-off between cost and advanced technology it is easy to focus on the traditional solutions. Although early adoption of Human Factors is often incorporated in the design phase, it is frequently overlooked as a specific means to derive significant cost savings during the wider build cycle and through-life operation of the vessel. This is perhaps unsurprising given that the Human Factors discipline within the maritime domain has traditionally tended to focus solely on the safety implications of vessel design and operation. The adoption of a human-centric approach to the design of vessels allows us to consider the whole system requirements of the crew in terms of supportability, operational effectiveness, habitability and survivability. At the same time this approach focuses attention on how the vessel supports the crew in their

ABSTRACTS 933

joint mission. Thus the modern warship must be seen as a partnership between the technology and human components within the system. This human-system integration approach allows us to not only focus on both human and system components within the design process, but also to take an inclusive stance across all parts of the marine design domains. Human-system integration is thus seen as an integral part of meeting the complex challenges posed by advanced technologies and the need to reduce cost.

Cost reduction Human factors engineering Naval vessels Ship design

2015102495

Survivability – the human element. Warship 2015: Future Surface Vessels, International Conference; 10-11 June 2015; Bath, UK. Organised by RINA, London, UK. [11 p, 29 ref, 1 tab, 4 fig] http://www.rina.org.uk/publications.html Pawling, R.J., Harmer, S., Et al English

Modern warship design is facing a number of drivers in terms of design, procurement and operation and these have both direct and indirect impacts on issues such as survivability and the human element. Guidance has been developed regarding Human Factors Integration (HFI), but this has generally focussed on detail design and fatigue. The UK MOD HFI Initiative describes HFI with 7 more holistic domains which are seen to have wider ship design impacts. This paper considers three current drivers on warship design for their impacts on survivability in the context of the human element. There were seen to be some interactions between different aspects of modern warship design and operation that again require a more holistic assessment of HF issues. The paper concludes that, although a more holistic approach is required, the increasing computerisation of the preliminary ship design process should allow tools to be developed to support this.

Human factors Naval vessels Ship design Survivability

2015102496

A new approach to the derivation of V-line criteria for a range of naval vessels. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 2, p 58 [9 p, 10 ref, 4 tab, 7 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Peters, A., Goddard, R., Dawson, N. English

Previous work has gone some way to understanding the applicability of the current naval V-lines standards to modern day naval designs by carrying out damaged vessel simulations using the CRN developed time-domain ship motion program FREDYN. The work presented in this paper seeks to further this understanding of V-lines by analysing the damaged motions of six vessel types, varying from a small Mine Counter Measure Vessel (MCMV) to a large auxiliary, and implementing a new methodology for the calculation of probabilistically derived dynamic motion allowances for heave and roll. Furthermore, analysis has been conducted in sea states up to a sea state 6 in order to understand the applicability of V-line criteria at greater wave heights and periods. This paper compares heave and roll allowances derived from the probability of exceeding water heights on the bulkheads bounding the damage in varying sea states for each vessel type, each with two damage cases at eight wave headings and at two speeds. Conclusions are drawn regarding the suitability of current criteria for vessels of varying size and design and their sensitivity to sea state.

Damage stability Design criteria Naval vessels

2015102497

Small combatant accidental damage extents. ISSW 2014, 14th International Ship Stability Workshop; 29 September-1 October 2014; Kuala Lumpur, Malaysia. Organised by Marine Technology Centre, Universiti Teknologi Malaysia. Session 2, p 67 [9 p, 10 ref, 7 tab, 4 fig] http://www.shipstab.org/index.php/conference-workshop-proceedings/issw2014-kuala-lumpur Marshall, S., Goddard, R., Et al English

Previous work has gone some way to understanding the applicability of the current naval V-lines

934 ABSTRACTS

standards to modern day naval designs by carrying out damaged vessel simulations using the CRN developed time-domain ship motion program FREDYN. The work presented in this paper seeks to further this understanding of V-lines by analysing the damaged motions of six vessel types, varying from a small Mine Counter Measure Vessel (MCMV) to a large auxiliary, and implementing a new methodology for the calculation of probabilistically derived dynamic motion allowances for heave and roll. Furthermore, analysis has been conducted in sea states up to a sea state 6 in order to understand the applicability of V-line criteria at greater wave heights and periods. This paper compares heave and roll allowances derived from the probability of exceeding water heights on the bulkheads bounding the damage in varying sea states for each vessel type, each with two damage cases at eight wave headings and at two speeds. Conclusions are drawn regarding the suitability of current criteria for vessels of varying size and design and their sensitivity to sea state.

Damage stability Design criteria Naval vessels

2015102498

Comparison between different survivability measures on a generic frigate. RINA Transactions - IJME - v 157 part A2, April-June 2015, p 125 http://www.rina.org.uk/ijme.html Liwång, H., Jonsson, H. English

Choosing suitable survivability measures is a demanding task that has to start early in the ship design process. Throughout the design process there is a need for compromises that will define and sometimes limit future operations or capabilities. In this study generic survivability measures are compared. The study also examines the sensitivity of the calculated probabilities to changes in the threat description. The result shows that it is important to investigate the total effect of a hit over a set of relevant ship functions defined for example by survivability levels. The calculations for different threat definitions show that the changes in survivability are substantial when the threat definition

is changed. Moreover, the effects of different hit assumptions differ between weapon types. This must be treated as an uncertainty which also should be reflected in the output and weighted into the decisions made, based on the survivability analysis.

Frigates Survivability

2015102499

Impact resistance assessment of shipboard equipment considering spectrum dip effect. MARSTRUCT 2015, 5th International Conference on Marine Structures; 25-27 March 2015; Southampton, UK. Published by CRC Press, ISBN 978-1-138-02789-3. Chapter 21 [8 p, 11 ref, 13 fig] https://www.crcpress.com/product/isbn/9781138027893 Yang, Y., Yu, M., Et al English

Due to the interaction between structural inertia force and impact input, spectrum dip effect exists in the impact environment of shipboard equipment. This phenomenon should not be ignored, because it can bring errors to impact resistance assessment results. In this paper, mass-spring system model was adopted to analyse the mechanism and influential factors of spectrum dip effect. Considering the fluid-structure coupling, the improved Taylor plate theory was employed to build an impact environment model of shipboard equipment. The spectrum dip effect occurs at the natural frequency of installed equipment, and spectrum dip amplitude becomes more obvious when equipment mass increasing. Compared to the BV reduction formula, the decline in spectrum value calculated by DDAM (Dynamic Design Analysis Method) is closer to the simulation value when equipment mass changes. The mounting frequency of equipment has little effect on the amplitude of spectrum dip. The model based on improved Taylor plate theory and mass-spring system can be used to assess the impact resistance performance of the shipboard equipment effectively when spectrum dip effect and fluid-structure coupling are both taken into consideration.

Equipment Impact strength Naval vessels Spectrum analysis

ABSTRACTS 935

6 MISCELLANEOUS

2015102500

The competitive advantage of maritime clusters. SOME 2015, 5th International Symposium on Ship Operations, Management & Economics; 28-29 May 2015. Organised by SNAME Greek Section. [10 p, 53 ref] http://www.sname.org/communities1/resources/viewtechnicalpaper/?DocumentKey=78eae9b9-ef7d-4ae8-bf6f-69ef84ae1f8c Stavroulakis, P.J., Papadimitriou, S., Koliousis, Y. English

Economic theory has long been indulged with the study of industrial clusters. The standards, threads and governing parameters of clusters provide a very fruitful area of study for a plethora of disciplines besides and beyond economics, such as strategic management, mathematics, life sciences and organizational management in general. Industrial clusters hold such a prominent position as decision-affecting entities, that in many frameworks they directly influence national and international policy in a basic level, through their needs and in a secondary level, through their linkages to other industries and their weight upon the economic cycle itself. Through this paper the authors attempt a critical examination as to the factors formulating the competitive advantage of industrial clusters and within a second focal direction, the competitive advantage of maritime clusters in particular. This work aspires to contribute to the body of knowledge with respect to maritime clusters from a strategic management standpoint.

Competitiveness Cooperation Maritime industries

AUTHOR INDEX A-1

Author Name Abstract No.

Abbaspoor, M. 2015102392 Abbaspour, M. 2015102372 Abdel-Maksoud, M. 2015102405 Acanfora, M. 2015102395 Adedpipe, O. 2015102483 Aga, H.L. 2015102468 Aggarwal, R. 2015102330 Agrawal, M. 2015102430 Aktas, B. 2015102378 Alcom, R. 2015102335 Allen, T. 2015102419 Amaral Amante, D. do 2015102466 Amdahl, J. 2015102476 Andersen, P.G. 2015102310 Antony, A. 2015102279 Ao, L. 2015102471 Arango-Turner, M. 2015102334 Aravossis, K. 2015102357 Arena, F. 2015102339 Arsenie, P. 2015102296 Atkinson, D.J. 2015102301 Avi, E. 2015102275 2015102452 Awda, H. 2015102294 Bahuguni, A. 2015102323 2015102448 Bajic, D. 2015102274 Ballini, F. 2015102362 Bangash, Z.A. 2015102440 Barbariol, F. 2015102333 Bari, S.J. 2015102293 Battley, M. 2015102419 Bauduin, C. 2015102321 Belenky, V. 2015102396 Benetazzo, A. 2015102333 Bennett, S.S. 2015102385 Berg, T.E. 2015102350 Bertoglio, C. 2015102286 2015102484 Bitner-Gregersen, E.M. 2015102416 Blake, J.I.R. 2015102343 Bodger, L. 2015102375 Boekhorst, A. 2015102325 Boireau, C. 2015102320 Bonnaffoux, G. 2015102332 Boonpratpai, P. 2015102453 Boulard, R. 2015102321 Boulougouris, E. 2015102366 Bratu, G.C. 2015102388 Brennan, F. 2015102483 Bretschneider, H. 2015102377 Brocco, E. 2015102454 2015102456 Brouwer, J. 2015102369

Buča, M.P. 2015102290 Burgherr, P. 2015102353 Cai, H. 2015102384 Camilleri, J. 2015102422 Carlton, J.S. 2015102462 Carral Couce, J.C. 2015102303 Carral Couse, L. 2015102303 Carvalho e Silva, D.F. de 2015102411 Castiglione, T. 2015102373 Chapchap, A.C. 2015102387 Chatzidouros, E.V. 2015102485 Chen, H. 2015102338 Chen, K. 2015102384 Chen, W. 2015102438 Chen, Y. 2015102439 Chen, Y-y. 2015102470 Chen, Z. 2015102424 Chen, Z-M. 2015102418 Cheon, J.S. 2015102441 Chin, C.K.H. 2015102356 Chroni, D. 2015102313 Chujutalli, J.A. 2015102466 Clabby, D. 2015102331 Clauss, G.F. 2015102414 Collette, M.D. 2015102283 Ćorak, M. 2015102386 Corres, A.J. 2015102300 Cristea, B. 2015102423 Croonenborghs, E. 2015102349 Cui, W. 2015102465 Cupsa, O.S. 2015102284 Curran, K.P. 2015102447 D’Souza, R.B. 2015102330 Daley, C. 2015102360 Darvishzadeh, T. 2015102426 Dauncey, G. 2015102297 Davies, A.J. 2015102354 Dawson, N. 2015102496 De Meo, D. 2015102455 Demirel, H. 2015102295 Dessi, D. 2015102412 Dikis, K. 2015102309 Dirksen, T. 2015102308 Diyaroglu, C. 2015102455 Doan, V-P. 2015102429 Domnisoru, L. 2015102423 Drouet, A. 2015102277 Du, Q. 2015102465 Dudek, M. 2015102414 Duggal, A.S. 2015102329 Dyrkoren, E. 2015102350 Eames, P. 2015102451 Ebrahimi, M. 2015102372 Edgarth, D.W. 2015102477

A-2 AUTHOR INDEX

Eidnes, G. 2015102337 2015102370 El Moctar, O. 2015102469 Eliopoulou, E. 2015102482 Epps, B.P. 2015102381 Ersdal, G. 2015102340 Estefen, S.F. 2015102466 Evers, K-U. 2015102480 Fagerholt, K. 2015102367 Faltinsen, O.M. 2015102428 Farmakis, E. 2015102482 Farrow, M. 2015102324 Feng, B. 2015102285 Fetisov, V.A. 2015102364 Fischer, C. 2015102486 2015102487 Floris, V.V. 2015102346 Floyd, H. 2015102356 Fonseca, N. 2015102391 Fragiadakis, N.G. 2015102292 Francisquez, M. 2015102381 Frangos, A. 2015102300 Frank, D. 2015102488 Fricke, W. 2015102460 2015102486 2015102487 Fu, S. 2015102437 Fu, T.C. 2015102446 Fuentes, S. 2015102282 Fuhr, C. 2015102334 Fujarra, A.L.C. 2015102434 Gaggero, S. 2015102286 2015102484 Gaiotti, M. 2015102276 2015102461 Galbraith, D. 2015102340 Gallego, V. 2015102379 Gao, D. 2015102478 Gao, Y. 2015102437 Gerlach, B. 2015102460 Ghelardi, S. 2015102276 Gibson, R. 2015102445 Girit, O. 2015102358 Gjerde, T. 2015102338 Gledić, I. 2015102386 Goddard, R. 2015102496 2015102497 Gonçalves, R.T. 2015102434 Gonzalez, L.M. 2015102440 González-Adalid, J. 2015102305 Gougoulidis, G. 2015102306 Grammatikaki, A. 2015102341 Greenbank, C. 2015102494 Grenestedt, J.L. 2015102447 Gu, M. 2015102402 2015102403

Guedes Soares, C. 2015102339 Guillerm, P-E. 2015102400 Gundermann, D. 2015102308 Guo, B. 2015102416 Gyllenhammar, E. 2015102320 Haas, R. de 2015102318 Haimov, H. 2015102379 Haley, J.F. 2015102445 Hamedifar, H. 2015102311 Hao, H. 2015102467 Hao, Z. 2015102285 Harmer, S. 2015102494 2015102495 He, J. 2015102449 He, W. 2015102373 Hearn, G.E. 2015102388 Heij, C. 2015102348 Hellesmark, S.B. 2015102310 Helma, S. 2015102375 2015102376 Hennig, J. 2015102369 Hickson, H. 2015102451 Hillerup, D. 2015102492 Hockberger, W. 2015102289 Hoogeland, M.G. 2015102272 Hooker, S. 2015102289 Hope, M.J. 2015102354 Horel, B. 2015102400 Hu, J.J. 2015102421 Hu, Y. 2015102449 Huang, W. 2015102431 Huera-Huarte, F.J. 2015102440 Islam, M. 2015102380 Ivaldi, A. 2015102273 Izadparast, A.H. 2015102329 Jafarzadeh, S. 2015102359 Jang, B.S. 2015102441 Jang, H. 2015102278 Ji, C. 2015102316 Jia, D. 2015102430 Jin, Q. 2015102389 Johannsen, C. 2015102377 Jonsson, H. 2015102498 Joo, W.H. 2015102479 Kaasen, K.E. 2015102317 Kadri, U. 2015102427 Kalinina, A. 2015102353 Kara, M.C. 2015102442 Karimi, M.H. 2015102392 Katsanis, I.S. 2015102299 Kawaida, D. 2015102398 Kazerooni, M.F. 2015102415 Khramushin, V. 2015102281 Kilic, A. 2015102358 Kim, H.S. 2015102287 Kim, H.W. 2015102479

AUTHOR INDEX A-3

Kim, J.W. 2015102278 Kim, S. 2015102418 2015102481 Kimiaei, M. 2015102477 Knapp, S. 2015102348 Kolios, A. 2015102483 Koliousis, Y. 2015102500 Kontolefas, L. 2015102394 Kougioumtzoglou, M.A. 2015102342 Kouh, J-S. 2015102374 Kurt, I. 2015102366 Laakso, A. 2015102452 Laface, V. 2015102339 Lakshmynarayanana, P. 2015102424 Lan, D. 2015102355 Langston, W.J. 2015102352 Lauritzen, F. 2015102302 Lazakis, I. 2015102309 2015102342 Lee, C.H. 2015102479 Lee, G.J. 2015102401 Lee, Y.-J. 2015102472 Leira, B.J. 2015102468 Lewis, T. 2015102335 Ley, J. 2015102469 Li, C. 2015102474 Li, L. 2015102343 Li, M. 2015102438 Li, W. 2015102431 Li, Y. 2015102382 Liang, B. 2015102355 Liao, P.-K. 2015102472 Lillemäe, I. 2015102275 Lin, T-Y. 2015102374 Lindstad, H. 2015102363 Liu, C. 2015102390 Liu, R.M. 2015102421 Liu, W. 2015102425 Liu, X. 2015102433 Liu, Y. 2015102283 Liu, Z. 2015102285 Liwång, H. 2015102498 Lotsberg, I. 2015102307 Lu, J. 2015102402 2015102403 Lu, S. 2015102345 Maimun, A. 2015102432 Maiorov, N.N. 2015102364 Majumder, M.R. 2015102298 Maki, K.J. 2015102408 Maliaga, E. 2015102351 Mallahzadeh, H. 2015102336 Manuel, L. 2015102473 Mao, D. 2015102450 Marshall, S. 2015102497 Martinas, G. 2015102284

Martinas, G. 2015102296 2015102383 Matusiak, J. 2015102395 McCall, A. 2015102331 McKesson, C.B. 2015102288 Medellin, A. 2015102334 Melis, C. 2015102332 Miller, J.D. 2015102324 Minna, S.S. 2015102412 Mocanu, C.I. 2015102423 Molynuex, D. 2015102380 Morabito, M.G. 2015102371 Moro, L. 2015102454 2015102456 Morter, P. 2015102344 Nakamura, M. 2015102399 Nakazawa, N. 2015102328 Nazarov, A. 2015102271 Nebbia, G. 2015102490 Nestegård, A. 2015102404 Nguyen, L.T.T. 2015102435 Nguyen, T.M. 2015102304 Nho, I. 2015102481 Nishi, Y. 2015102429 O’Driscoll, MA. 2015102324 O’Shea, T.T. 2015102446 Oberhagemann, J. 2015102420 Odeskaug, L. 2015102319 Ölçer, A. 2015102362 Ommani, B. 2015102428 Östman, A. 2015102409 2015102410 Oterkus, E. 2015102455 Ozaki, M. 2015102328 Pagiaziti, A. 2015102351 Pakozdi, C. 2015102409 2015102410 2015102413 2015102444 Pallis, A.A. 2015102315 Pang, F.Z. 2015102457 Papachristou, A.A. 2015102315 Papachristou, Y. 2015102300 Papadimitriou, S. 2015102500 Papandreou, C. 2015102291 Papanikolaou, A. 2015102291 2015102482 Park, K.D. 2015102287 Park, Y.C. 2015102279 2015102280 Parunov, J. 2015102386 Pawling, R.J. 2015102495 Pedersen, E. 2015102359 Peltonen, M. 2015102491 Pérez Sobrino, G. 2015102305 Pessoa, J. 2015102391

A-4 AUTHOR INDEX

Peters, A. 2015102496 Peters, W.S. 2015102396 Pham, H.T. 2015102304 Phillips, A.B. 2015102385 Plessas, T. 2015102313 Poll, P. 2015102280 Pope, N.D. 2015102352 Pothuganti, V.K. 2015102329 Psaraftis, H.N. 2015102367 Qian, P. 2015102382 Radon, M. 2015102420 Ramli, M.Z. 2015102368 Reed, A.M. 2015102397 Remes, H. 2015102488 2015102491 Ren, H. 2015102474 Richards, D. 2015102494 Rijtema, S. 2015102318 Riska, K. 2015102365 Rizzo, C.M. 2015102276 2015102461 2015102487 2015102490 Roesler, B.T. 2015102381 Romanoff, J. 2015102488 Rossi, R.R. 2015102411 Ryan, R. 2015102380 Ryu, J. 2015102314 Salas, M. 2015102282 Salio, M.P. 2015102463 Sandaas, I. 2015102363 Santhanamuthu, T. 2015102294 Saraiva, T.C. 2015102326 Sari, A. 2015102426 Sasaki, N. 2015102375 Sauder, T. 2015102349 Sazidy, M. 2015102360 Schiller, R.V. 2015102413 2015102444 Schinas, O. 2015102370 Schmidt, D. 2015102473 Schmittner, C. 2015102369 Schofield, P. 2015102430 Schoop-Zipfel, J. 2015102405 Sciberras, E.A. 2015102301 Seif, M.S. 2015102392 2015102415 Selvik, Ø. 2015102407 Semijalac, G. 2015102290 Shabaka, A.E. 2015102294 Sharp, J. 2015102340 Sheng, W. 2015102335 Shiken, D. 2015102399 Shinb, Y-S. 2015102475 Siddiqui, A.W. 2015102361 Sigurdsson, G. 2015102307

Sivalingam, K. 2015102448 Sørensen, K.F. 2015102492 Spada, M. 2015102353 Spitzenberger, C. 2015102311 Sprenger, F. 2015102407 Spyrou, K. 2015102396 Spyrou, K.J. 2015102394 Stansberg, C.T. 2015102317 Stavrou, D.I. 2015102312 Stavroulakis, P.J. 2015102500 Steenson, B. 2015102325 Stefanakos, C.N. 2015102337 2015102370 Stoesser, T. 2015102442 Storheim, M. 2015102476 Strømman, A.H. 2015102363 Stuppe, S. 2015102414 Subramanian, R. 2015102330 Swan, C. 2015102445 Tan, J.H.C. 2015102436 Tan, M. 2015102343 2015102368 Tang, W. 2015102425 Taunton, D.J. 2015102422 Temarel, P. 2015102368 2015102387 2015102422 2015102424 2015102435 Teng, Y.J. 2015102436 Themelis, N. 2015102394 Thilleul, O. 2015102277 Thorsen, T.B. 2015102310 Tian, Z. 2015102458 Tinsley, D. 2015102253 2015102254 Tofa, M.M. 2015102432 Toro, L.F.B. 2015102326 Travanca, J. 2015102467 Tregde, V. 2015102404 Tsereklas-Zafeirakis, A. 2015102357 Tsiourva, T. 2015102485 Tule, J. 2015102327 Turan, O. 2015102366 Turkmen, S. 2015102378 Uğurlu, Ö. 2015102347 Umeda, N. 2015102398 2015102402 Underwood, J.M. 2015102451 Ünlügençoğlu, K. 2015102295 Valkonen, J. 2015102365 Vasileiadis, N. 2015102306 Velde, H. van der 2015102325 Ventikos, N. 2015102341 Ventikos, N.P. 2015102312 Verma, M. 2015102361

AUTHOR INDEX A-5

Voormeeren, L.O. 2015102464 Vredeveldt, A.W. 2015102272 Walrre, F. van 2015102401 Walters, C.L. 2015102464 Wang, B. 2015102475 Wang, D. 2015102471 Wang, F. 2015102459 Wang, T. 2015102403 Wang, X. 2015102475 Wang, X.L. 2015102421 Wang, Y. 2015102336 2015102433 Weihs, D. 2015102427 Wilson, P.A. 2015102418 Wooliscroft, M.O. 2015102408 Wu, G.X. 2015102443 Wu, W. 2015102322 Wu, Y. 2015102323 2015102439 Xiong, Y. 2015102459 Xiong, Y.P. 2015102453 Xu, G.D. 2015102443 Xue, H. 2015102425 Xue, Y.Z. 2015102457 Yan, P. 2015102458 Yang, J. 2015102406 Yang, Y. 2015102499 Yao, X. 2015102470 Yfantis, E. 2015102299 Yi, H. 2015102382 Yi, Q. 2015102489 Yildirum, U. 2015102347 Yin, J. 2015102390 Yoshimura, Y. 2015102399 You, Y-x. 2015102431 Yu, D. 2015102417 Yu, M. 2015102499 Yuan, Z. 2015102316 Yue, Y. 2015102489 Yun, S 2015102314 Zahawi, B. 2015102301 Zaky, M. 2015102393 Zarbock, O. 2015102377 Zeng, J. 2015102322 Zhang, J. 2015102345 2015102478 Zhang, S. 2015102389 Zhang, Y. 2015102417 Zhao, W. 2015102406 Zhong, C. 2015102450 Ziemer, G. 2015102480 Zou, Z. 2015102390 Zuzick, A.V. 2015102397

SHIP AND STRUCTURE NAME INDEX S-1

Ship/Structure Name Abstract No.

Andalucian Zephyr 2015102255 Asia Vision 2015102256 Atlantic Gas 2015102257 Balt Flot 1 2015102258 Berkarar 2015102259 Burgan 2015102260 Cascade 2015102261 CCNI Iquique 2015102262 CDC Heron 2015102251 Ceona Amazon 2015102253 2015102263 Charlotte Schulte 2015102264 Copiapo 2015102265 Corcovado LNG 2015102266 Costa Diadema 2015102267 Crystal Star 2015102268 CSCL Globe 2015102269 Deepwater Asgard 2015102270 Stena Impression 2015102254

KEYWORD INDEX K-1

Keyword Abstract No.

Accident investigations 2015102344 Accident research 2015102347 Accommodation spaces 2015102252 2015102345 Acoustics 2015102379 Aerodynamics 2015102447 2015102448 Ageing offshore structures 2015102340 Air 2015102322 2015102401 Air pollution 2015102304 2015102362 Algorithms 2015102285 Alternative energy sources 2015102294 Aluminium 2015102282 Anchor handling vessels 2015102324 Anchor windlasses 2015102303 Angle bars 2015102489 Antifouling coatings 2015102352 2015102492 Approximation 2015102391 Arc welding 2015102485 Arctic environment 2015102321 Arctic transportation 2015102365 Auxiliary systems 2015102295 Ballast tanks 2015102493 Barents Sea 2015102350 Barges 2015102251 2015102252 Bayes theorem 2015102354 Beam seas 2015102411 Bearing capacity 2015102474 Berthed vessels 2015102301 Blowouts 2015102341 Boundary element method 2015102463 Bows 2015102393 2015102420 Box shapes 2015102471 Broaching 2015102396 2015102399 2015102400 Broadband 2015102462 Bronzes 2015102484 Buckling 2015102461 Bulk carriers 2015102255 2015102261 2015102268 2015102357 2015102421 2015102423 Bulkheads 2015102489 Butt welds 2015102487 Carbon dioxide 2015102328 2015102356

Cargo handling 2015102313 Cargo pumps 2015102313 Cargo ships 2015102258 Catamarans 2015102271 2015102373 2015102382 2015102457 Cavitation 2015102470 Cavitation inception 2015102377 Cavitation tests 2015102377 2015102378 Chemical tankers 2015102254 2015102260 2015102366 Classification society rules 2015102274 Coastal regions 2015102355 Coastal shipping 2015102358 Collapse 2015102477 Collision resistance 2015102272 2015102468 2015102476 2015102478 Columns (supports) 2015102473 Comfort 2015102454 Competitiveness 2015102500 Compliance costs 2015102363 Composite materials 2015102276 2015102419 2015102455 2015102490 Compressive strength 2015102466 Computational fluid dynamics 2015102277 2015102278 2015102286 2015102323 2015102374 2015102404 2015102408 2015102409 2015102410 2015102411 2015102414 2015102420 2015102422 2015102424 2015102426 2015102430 2015102435 2015102436 2015102446 2015102448 Computer-aided ship design 2015102291 Condition monitoring 2015102309 Containerised shipping 2015102364

K-2 KEYWORD INDEX

Containerships 2015102262 2015102264 2015102265 2015102269 2015102351 2015102374 2015102403 2015102472 Control surfaces 2015102392 Controllers 2015102390 Cooperation 2015102500 Corrosion fatigue 2015102483 Cost reduction 2015102494 Coupled motion 2015102406 2015102438 Crack propagation 2015102483 2015102486 Cracks 2015102471 Crossflow 2015102428 2015102435 Crude oil 2015102361 Cruise ships 2015102267 2015102274 2015102463 Cyclic loads 2015102450 Cylindrical bodies 2015102319 2015102418 2015102430 2015102432 2015102433 2015102434 2015102435 2015102440 2015102442 2015102445 2015102480 Cylindrical shells 2015102459 Damage 2015102386 2015102453 2015102464 2015102466 Damage stability 2015102496 2015102497 Decision making 2015102362 Decision support systems 2015102313 2015102354 Decision theory 2015102295 Deck wetness 2015102393 2015102409 2015102410 2015102411 2015102413 2015102444 Deepwater 2015102318 2015102320 2015102322

Deepwater 2015102326 2015102329 2015102330 Deformation 2015102458 Design 2015102286 2015102314 2015102332 2015102381 2015102384 Design criteria 2015102274 2015102496 2015102497 Design process 2015102277 Diesel engines 2015102295 2015102299 2015102456 Distortion 2015102474 Drift forces 2015102417 Drillships 2015102270 Drydocking 2015102308 Ducted propellers 2015102383 Ducts 2015102284 Dynamic analysis 2015102423 2015102478 Dynamic positioning 2015102338 2015102388 Dynamic response 2015102336 2015102412 2015102438 2015102440 2015102450 2015102456 Economic analysis 2015102357 Effective width 2015102276 Efficiency 2015102306 2015102357 2015102359 Elastic bodies 2015102425 Elastic properties 2015102469 Electric drives 2015102380 Electric power 2015102293 2015102301 Electric propulsion 2015102298 Emergencies 2015102350 Emergency response systems 2015102350 Emissions 2015102296 2015102300 2015102304 2015102358 2015102363 2015102367 Enclosed spaces 2015102451 Energy absorption 2015102467 2015102468 Energy conservation 2015102305 2015102306

KEYWORD INDEX K-3

Energy conservation 2015102357 2015102359 Energy consumption 2015102359 Energy dissipation 2015102375 English Channel 2015102352 Environmental effects 2015102352 Environmental protection 2015102352 2015102367 Equipment 2015102499 Estimating 2015102356 Excitation 2015102462 Exhaust gases 2015102304 2015102358 Experimentation 2015102323 2015102412 2015102434 2015102437 2015102445 2015102490 Explosions 2015102470 Extreme seas 2015102416 Extreme waves 2015102323 2015102477 Fabrication 2015102280 2015102327 Failure 2015102338 Fatigue (materials) 2015102473 Fatigue cracks 2015102307 2015102483 2015102485 Fatigue life 2015102423 2015102472 2015102486 2015102488 2015102489 Fatigue strength 2015102286 2015102484 2015102486 2015102487 2015102491 Fatigue tests 2015102487 2015102489 2015102491 Fault detection 2015102295 Fault trees 2015102292 Feasibility 2015102365 Ferries 2015102259 2015102288 2015102289 2015102297 Fillers 2015102490 Finite difference method 2015102429 Finite element method 2015102276 2015102286 2015102424 2015102461

Finite element method 2015102463 2015102465 2015102466 2015102475 Fishing vessels 2015102356 Flexible materials 2015102419 Flexible structures 2015102424 Floating bodies 2015102391 2015102424 Floating docks 2015102310 Floating production systems 2015102319 2015102321 2015102324 2015102325 2015102326 2015102329 Floating structures 2015102322 2015102332 2015102412 Flooding 2015102334 2015102401 Fluid structure interaction 2015102426 2015102429 2015102430 2015102442 Foil propellers 2015102381 Foils 2015102372 Following seas 2015102399 Forces 2015102428 Forecasting 2015102370 Forward speed 2015102416 Foundations 2015102478 Four stroke engines 2015102299 FPSOs 2015102326 2015102329 2015102388 2015102404 2015102409 2015102410 2015102411 2015102413 2015102444 2015102466 Free surfaces 2015102368 2015102408 Freeboard 2015102393 Frequency converters 2015102301 Frigates 2015102498 Fuel consumption 2015102366 Fuel costs 2015102358 Fuel tanks 2015102468 Fuzzy systems 2015102295 Gaps 2015102322 Gas fields 2015102320 Gas industry 2015102346 Gas turbines 2015102296

K-4 KEYWORD INDEX

Girders 2015102471 Graphic methods 2015102359 Groundings 2015102351 Heat affected zone 2015102483 Heat recovery 2015102299 Heat transfer 2015102345 Heaving 2015102387 Heavy lift vessels 2015102253 Heavy weather 2015102317 Heel (list) 2015102449 Height 2015102393 High speed vessels 2015102289 2015102392 2015102422 2015102447 High strength steel 2015102465 2015102491 Hull appendages 2015102284 2015102306 Hull cleaning 2015102308 Hull damage 2015102385 Hull form 2015102281 2015102287 2015102291 2015102319 Hull girders 2015102469 2015102474 Hull resistance 2015102371 Hulls 2015102458 Human factors 2015102495 Human factors engineering 2015102494 Hydrodynamic loads 2015102446 Hydrodynamics 2015102368 Hydroelasticity 2015102419 2015102421 2015102423 2015102424 2015102472 Ice 2015102480 Ice conditions 2015102281 Ice forces 2015102481 Ice resistance 2015102287 Ice strengthening 2015102468 Ice transiting vessels 2015102365 Icebreakers 2015102481 Icebreaking 2015102287 2015102360 Impact loads 2015102419 2015102422 2015102445 2015102446 Impact strength 2015102499 Inert gas generators 2015102302 Inert gas systems 2015102302 Injection 2015102328 Inshore 2015102337

Inspection 2015102307 Installing 2015102324 2015102327 2015102334 Interactions 2015102427 2015102481 Irregular waves 2015102394 2015102413 2015102430 Jacket structures 2015102450 2015102478 Jackup platforms 2015102251 Large tankers 2015102482 Laser welding 2015102485 2015102488 Launching 2015102349 Lifeboats 2015102349 2015102404 Liquefied gases 2015102328 Liquefied natural gas 2015102300 2015102319 2015102325 LNG carriers 2015102256 2015102266 2015102475 LNG handling 2015102310 LNG tanks 2015102272 2015102425 LNG terminals 2015102310 2015102311 2015102314 LNG transportation 2015102311 Loads (forces) 2015102455 2015102469 LPG carriers 2015102257 Machinery maintenance 2015102309 Manoeuvrability 2015102407 Manoeuvring 2015102405 2015102408 2015102415 Marine accidents 2015102348 Marine engineering 2015102277 Maritime industries 2015102500 Masts 2015102461 Mathematical analysis 2015102405 Mathematical models 2015102364 2015102394 2015102396 2015102402 2015102403 2015102418 Mechanical properties 2015102490 Mobile platforms 2015102338 Model tests 2015102290 2015102369 2015102379

KEYWORD INDEX K-5

Model tests 2015102380 2015102385 2015102398 2015102399 2015102400 2015102401 2015102402 2015102403 2015102406 2015102415 2015102436 2015102440 2015102480 Monte Carlo method 2015102366 Moored structures 2015102412 Moored vessels 2015102389 Mooring lines 2015102316 2015102317 Mooring systems 2015102316 2015102321 2015102324 2015102332 Motion 2015102391 2015102404 Motor yachts 2015102273 2015102454 Multibody systems 2015102343 2015102417 2015102427 Naval vessels 2015102494 2015102495 2015102496 2015102497 2015102499 Navigation channels 2015102415 Neural networks 2015102390 2015102459 Noise 2015102457 Numerical analysis 2015102290 2015102332 2015102335 2015102360 2015102373 2015102380 2015102387 2015102413 2015102423 Numerical models 2015102278 2015102343 2015102368 2015102389 2015102395 2015102398 2015102400 2015102412 2015102432

Numerical models 2015102433 2015102439 2015102456 Ocean waves 2015102333 Oceangoing river vessels 2015102258 Oceanographic data 2015102348 Offshore 2015102337 Offshore drilling 2015102318 Offshore engineering 2015102277 2015102426 Offshore industries 2015102294 2015102318 Offshore platforms 2015102279 2015102280 2015102293 2015102327 2015102330 2015102334 2015102431 2015102450 2015102477 2015102479 Offshore structures 2015102307 2015102336 2015102341 2015102349 2015102439 2015102441 2015102473 Oil spills 2015102353 2015102354 2015102355 Oil tankers 2015102347 Oil transfer 2015102312 Oil transportation 2015102361 Onshore 2015102301 Openings 2015102460 Optimisation 2015102282 2015102283 2015102284 2015102285 2015102290 2015102291 2015102313 2015102367 2015102381 Oscillations 2015102372 2015102435 Passenger ships 2015102275 2015102351 2015102460 Passenger terminals 2015102315 Performance 2015102335 Personnel accidents 2015102292 Petroleum industry 2015102346 Pipelaying vessels 2015102253

K-6 KEYWORD INDEX

Pipelaying vessels 2015102263 Pitching 2015102402 2015102448 Planing hulls 2015102371 2015102392 Planning 2015102307 Plates 2015102491 Platform accidents 2015102340 2015102341 Platform decks 2015102439 Platform design 2015102278 2015102279 2015102280 2015102327 Platform motions 2015102316 2015102436 Platform rammings 2015102341 2015102467 2015102476 Pods 2015102380 Polishing 2015102308 Pollution response systems 2015102354 Port facilities 2015102315 Position (location) 2015102272 Potential flow 2015102427 Power requirements 2015102293 2015102407 Power supplies 2015102293 2015102294 2015102297 2015102301 Pressure 2015102401 Probabilistic methods 2015102307 2015102338 Probability 2015102309 Probability distribution functions 2015102336 Products tankers 2015102254 2015102260 Propeller cavitation 2015102375 2015102378 2015102383 2015102462 Propeller cleaning 2015102308 Propeller efficiency 2015102375 2015102376 2015102384 Propeller hubs 2015102384 Propeller loading 2015102375 Propeller models 2015102376 Propeller noise 2015102378 2015102379 2015102463 Propeller vibration 2015102375 Propellers 2015102286 2015102484 Propulsion systems 2015102458

Propulsive efficiency 2015102290 2015102305 2015102372 2015102381 Propulsive performance 2015102380 Quartering seas 2015102395 2015102399 Rankine cycle 2015102299 Rectangular plates 2015102453 Reduction 2015102296 2015102304 Regulations 2015102362 2015102363 Reliability 2015102309 Resilient mountings 2015102456 Resistance 2015102373 2015102382 Resonance 2015102417 2015102442 Resonant frequency 2015102452 Restricted waters 2015102415 Retrofitting 2015102305 2015102357 Risers 2015102429 2015102437 2015102438 Risk 2015102351 Risk analysis 2015102292 2015102309 2015102311 2015102312 2015102342 2015102347 2015102348 Ro/ro ships 2015102259 Rolling 2015102395 2015102402 2015102403 2015102406 Rotors 2015102448 Safety 2015102346 2015102451 Sail assisted vessels 2015102449 Sailing vessels 2015102461 Sails 2015102449 Sandwich panels 2015102488 Scale effect 2015102374 2015102376 2015102377 2015102401 Scheduling 2015102361 2015102364 Scrubbers 2015102300 Sea ice 2015102481 Sea state 2015102332 2015102454

KEYWORD INDEX K-7

Seakeeping 2015102281 2015102382 2015102386 2015102392 2015102393 2015102397 2015102414 Search and rescue 2015102350 Self propulsion 2015102374 Semisubmersibles 2015102278 2015102326 2015102330 2015102441 2015102473 Shell structures 2015102464 2015102465 2015102466 Ship collisions 2015102351 Ship design 2015102271 2015102272 2015102273 2015102274 2015102275 2015102281 2015102282 2015102283 2015102284 2015102285 2015102287 2015102288 2015102289 2015102494 2015102495 Ship hydrodynamics 2015102387 Ship motions 2015102386 2015102389 2015102392 2015102394 2015102396 2015102399 2015102400 2015102430 Ship performance 2015102365 2015102366 Ship response 2015102385 2015102416 Ship routing 2015102361 Ship simulators 2015102344 Ship speed 2015102360 2015102367 Ship structures 2015102462 2015102470 2015102486 Shipboard fires 2015102345 Shipbuilding 2015102292 Shipping 2015102362

Shipping 2015102363 Ships 2015102328 Shipyard safety 2015102292 Shock 2015102455 2015102470 Short sea trades 2015102358 Silicons 2015102492 Simulation 2015102364 2015102365 2015102397 2015102407 Sinkage 2015102373 Slamming 2015102419 2015102422 2015102441 Slamming 2015102420 Slender bodies 2015102427 2015102428 Slender body theory 2015102427 Sloshing 2015102406 2015102425 Solitary waves 2015102431 Space requirements 2015102451 Spectrum analysis 2015102499 Spill risk 2015102353 2015102355 Sponsons 2015102447 Springing 2015102472 Stability 2015102395 2015102396 2015102398 2015102403 2015102449 Stationkeeping 2015102329 Statistical analysis 2015102308 2015102482 Steel 2015102485 Steel structures 2015102483 Stiffened plates 2015102276 2015102452 Stiffeners 2015102487 Stiffness 2015102460 Stochastic processes 2015102333 Storage 2015102328 Storms 2015102339 Stresses 2015102464 2015102469 Structural analysis 2015102275 2015102282 2015102451 Structural failure 2015102482 Structural reliability 2015102473 Structural response 2015102460 2015102462 2015102465 2015102470

K-8 KEYWORD INDEX

Structural response 2015102481 Structural strength 2015102475 Subcritical flow 2015102433 Superstructures 2015102273 Supports 2015102425 Suppression 2015102437 Surging 2015102396 2015102402 Survivability 2015102495 2015102498 SWATH ships 2015102291 2015102382 Swaying 2015102438 Tandem arrangement 2015102310 2015102442 Tank coatings 2015102493 Tanker accidents 2015102347 2015102353 Tankers 2015102290 2015102313 2015102361 Tanks 2015102334 Tension leg platforms 2015102436 Theory 2015102452 Thin plates 2015102453 2015102491 Thrust deduction 2015102374 Time series analysis 2015102370 Tip loaded propellers 2015102305 Tip vortices 2015102377 Torsion 2015102471 Tracking 2015102390 Transients 2015102414 Transition flow 2015102418 Treatment 2015102304 Trim 2015102373 Trimarans 2015102282 Tug barge systems 2015102298 Turbulence 2015102418 Ultimate strength 2015102471 2015102474 Uncertainty 2015102283 Underwater 2015102455 2015102457 2015102459 Underwater acoustics 2015102463 Validation 2015102397 2015102398 Variability 2015102339 Vessel descriptions 2015102251 2015102252 2015102253 2015102254 2015102255 2015102256 2015102257

Vessel descriptions 2015102258 2015102259 2015102260 2015102261 2015102262 2015102263 2015102264 2015102265 2015102266 2015102267 2015102268 2015102269 2015102270 Vessels 2015102390 Vibration 2015102453 2015102454 2015102458 2015102459 2015102480 Vibration analysis 2015102275 Vibration damping 2015102479 Vortex induced vibration 2015102429 2015102432 2015102433 2015102434 2015102437 2015102438 2015102440 Vortex shedding 2015102443 Vortices 2015102436 Voyage data 2015102344 Wall effects 2015102415 Waste disposal 2015102315 Water entry 2015102443 Wave absorbers 2015102343 Wave climate 2015102337 Wave data 2015102370 Wave direction 2015102339 Wave energy conversion 2015102331 2015102335 2015102343 Wave forces 2015102317 Wave forces on ships 2015102405 Wave groups 2015102369 Wave height 2015102348 Wave loads 2015102409 2015102410 2015102411 2015102413 2015102420 2015102444 Wave loads on ships 2015102386 2015102421 Wave loads on structures 2015102431 2015102439 2015102445

KEYWORD INDEX K-9

Wave loads on structures 2015102477 Wave models 2015102278 2015102337 Wave propagation 2015102368 Wedges 2015102443 2015102446 Welded joints 2015102485 2015102486 Wigley models 2015102387 Wind 2015102333 2015102370 Wind conditions 2015102348 Wind loads 2015102349 Wind tunnel tests 2015102447 2015102449 Wind turbines 2015102342 2015102448 2015102478 Windows 2015102460 Wing in ground effect craft 2015102289

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