Development of a parametric model for analysing ...m120.emship.eu/Documents/MasterThesis/2014/VIVEK...

Development of a parametric model for analysing temperature effects of

solar radiation on yachts

Vivek Kumar EMSHip Week – Master Thesis Presentation

17th February 2014, La Spezia, Italy

The perfection of a yacht's beauty is that nothing should be there for only beauty's sake.

John MacGregor, Scottish explorer and designer of the first modern sailing canoes

VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 2

Introduction

•The Problem

•Research Methodology

Experimental Measurements

Development of the Parametric Model

•Solar Ray Tracing

•Heat Transfer and Temperature Calculation

Results and Analysis

Effects of High Temperatures

Solutions and Implementation

Plans Conclusions Question Time

INTRODUCTION

▪ Why is a yacht typically white ?


Cheaper

Forgives Imperfections

Does not excessively glitter and reflect

Dark surfaces show more dirt and splashes

Doesn’t fade so fast

Pseudo-standard

MUCH COOLER under solar radiation

▪ Aesthetics is all about Engineering

▪ Gap between Looks - Colour choice - Material choice – Temperature Effects - Engineering

The colour of the hull paint

The intensity of solar radiation

The effects of shading from the sun

The temperatures of the surrounding water and air

The temperature of air and liquids within the ship

The effects of wind and waves in dissipating heat

Extremely high temperatures of the welding process during fabrication

MEASUREMENTS


White

Ship

Dark-Blue

Ship

SUMMER WINTER

Blue

• 30-40

• 40-60

• 60-80

White

• 30-40

• 40-60

• 60-80

Blue

• 30-40

• 40-60

• 60-80

White

• 30-40

• 40-60

• 60-80

VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy

MEASUREMENTS – Temperature Variation

5

Time of

Day Blue Ship [Port] White Ship [Port] Blue Ship [Stern] White Ship [Stern]

Blue Ship

[Starboard]

White Ship

[Starboard] Blue Ship [Bow] White Ship [Bow]

0800

Not Available

0900

1000

1100

1200


Longitudinal temperature variation

Vertical temperature variation


Port temperature variation Starboard temperature variation

Dark

-Blu

e S

hip

S

ilver

Gre

y S

hip

W

hite S

hip


1. Perform Solar Ray Tracing

•Sun Elevation

•Sun Azimuth

2. Calculate Ship Geometry

•Panel creation

•Ship-surface azimuths and tilt angles

3. Calculate Heat Transfers

•Energy Balance

•Surface Temperatures

4. Parametric Evaluations

5. Calculate Temperature Effects

•Deflections

•Optical Distortions

•Energy Usage

DEVELOPMENT OF THE PARAMETRIC MODEL

Experimental Setup


Panel Front Side (above) Back side (below)

Part Dimensions

Plate 1000mm x 400mm

Epoxy Layer Test-1 : 10mm / Test-2 : 20mm

Aluminium 5083

H111 Layer

5mm

Transverse

Frames

200mm x 5mm (Web)

Longitudinal

Stringer

60mm x 4mm (Web), 60mm x 4mm

(Flange)

Lamp Halogen Lamp capable of 450°C,

fixed 500mm from the plate for

simulating temperature of 65°C

(corresponding to black colour)

1. Solar Ray Tracing


1. Selection of the ASHRAE model

1. Practical to use

2. Available data

3. Well-established methods

Theoretical modelling

External Reference

2. Ship Geometry


Tilt Angle

Surface Azimuth Angle


3. Heat Transfers

𝑇𝑠4 𝜖𝜎𝐴 + 𝑇𝑠 ℎ𝑐𝐴 +

1

ℎ𝑠 − ℎ𝑤+

1

Roverall − 𝜖𝜎𝐴𝑇𝑠𝑘𝑦

4 + ℎ𝑐𝐴𝑇∞ +𝑇𝑠ℎ𝑖𝑝

Roverall+

𝑇𝑤ℎ𝑠 − ℎ𝑤

= 0


Parametric Analysis


Heat Transfers

Time of Day [hour]

Month

Bulwark : Starboard Black Surface Temperature Variation

5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month

Bulwark: Starboard White Surface Temperature Variation

5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month

Bulwark : Port Black Surface Temperature Variation

5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month

Bulwark: Port White Surface Temperature Variation

5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Effect of Paint Colour


1 2 3 4 5 6 7 8 9 10 11 1210

15

20

25

30

35

40

Months

Tem

pera

ture

[D

eg C

]

Maximum Monthly Layer Temperature Variation | Ship Heading = -106 degrees

Paint-Epoxy (SB)

Epoxy-Metal (SB)

Metal-Insulation (SB)

Paint-Epoxy (SW)

Epoxy-Metal (SW)

Metal-Insulation (SW)

Ship Temp Black

Ship Temp White

1 2 3 4 5 6 7 8 9 10 11 1220

25

30

35

40

45

50

55

Months

Tem

pera

ture

[D

eg C

]

Maximum Monthly Layer Temperature Variation | Ship Heading = -106 degrees

Paint-Epoxy (PB)

Epoxy-Metal (PB)

Metal-Insulation (PB)

Paint-Epoxy (PW)

Epoxy-Metal (PW)

Metal-Insulation (PW)

Black Ship Int Temp

White Ship Int Temp

Surface

Colour

Fraction of

Incident Radiation

Absorbed

White

smooth

surfaces

0.25 - 0.40

Grey to dark

grey 0.40 - 0.50

Green, red

and brown 0.50 - 0.70

Dark brown

to blue 0.70 - 0.80

Dark blue to

black 0.80 - 0.90

Ship berthed on land and water


1 2 3 4 5 6 7 8 9 10 11 1210

15

20

25

30

35

40

45

50

55

60

In Water

Tem

pera

ture

[deg C

]

Maximum Temperature per month when the ship is In/Out Water

In Water (SB)

In Water (SW)

In Water (PB)

In Water (PW)

Out of Water (SB)

Out of Water (SW)

Out of Water (PB)

Out of Water (PW)

Effect of Sun Elevation


2 4 6 8 10 12 14 16 18 20 22 240

10

20

30

40

50

60

Hours

Tem

pera

ture

[D

eg C

]Annual Hourly Temperature Variation | Starboard | Black Paint

2 4 6 8 10 12 14 16 18 20 22 240

10

20

30

40

50

60

Hours

Tem

pera

ture

[D

eg C

]

Annual Hourly Temperature Variation | Port | Black Paint

2 4 6 8 10 12 14 16 18 20 22 240

10

20

30

40

50

60

Hours

Tem

pera

ture

[D

eg C

]

Annual Hourly Temperature Variation | Starboard | White Paint

2 4 6 8 10 12 14 16 18 20 22 240

10

20

30

40

50

60

Hours

Tem

pera

ture

[D

eg C

]

Annual Hourly Temperature Variation | Port | White Paint

Jan

Feb

Mar

Apr

May

Jun

Jul

Aug

Sep

Oct

Nov

Dec

Effect of the incidence angle

on the reflectivity of water (Hechtman, 1956)

Ground reflectance values

of typical surfaces (ASHRAE,2009)

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60


-180 +90

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

-90

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Effect of Ship Heading Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

Time of Day [hour]

Month


5 10 15 20

2

4

6

8

10

12

0

10

20

30

40

50

60

-164

Effects of High Temperatures

▪ Hull Deformations

▪ Optical Distortion Effects

▪ Hull Coating Defects

▪ Increased Cooling Loads

▪ Internal Hull Surface Condensation

▪ Thermal Comfort


Deflections


DEFLECTIONS


Section of

ship Plate Zone

Max

[mm

]

Avg.

[mm] Remarks

Aft

Bulwark 0.5 0 -

Mid-plating 6 3 Bulge near engine room bulkhead

Bottom-plating 2 2 -

Midships

Bulwark 1 0.5 -

Mid-plating 5 2 4-6mm deflections near portholes

Bottom-plating 3 2 -

Fore

Bulwark 0.5 0

Bow area under chine not measured Mid-plating 2 1

Bottom-plating 1 0.5

Deformation Analysis


Port Side (Sun Exposed)

Starboard Side (In Shade)

Engi

ne R

oom

Bul

khea

d

Ster

n En

d

Bow

End

Porthole

mode shape between frames

mode shape between bulkheads

Optical Distortion Effects


Optical Distortion


F2F F' 2F'

virtual , upright & magnified imageobject

Heated Air

CoolerAir

deviation

Other Effects of Temperature


Fuel consumption variation with load

(DieselService&Supply, 2014)

Hull Coating Defects


Solutions and Implementations

TRIZ (Theory of Inventive Problem Solving)


SUPER SYSTEM

Sun

Atmosphere

Water

Ship Hull

Other Ships / Dock

Mooring Fenders

SYSTEM

Paint

Epoxy

Primer

Metal

Insulation

Interior Air

Air Conditioner

Generator

SUB SYSTEM

Paint Pigment

Paint Topcoats

Paint Undercoats

Epoxy Fine Layer

Epoxy Coarse Layer

Primer

Stiffners and Panels

Insulation Layers

Process Analysis

• Root Cause Analysis

• Functional Analysis

Problem Analysis

• Model of Problem

• Determination of ideal final result

• Physical contradictions

• Inventive Principles

Concept Evaluation & Selection

Concept Test Plan

Concept Implementation


Aesthetics destroyed

Increased visibility of hull surface deflections

Uneven surface profile

Thermal Expansion of epoxy and metal

(This branch is the same for analysing Increased Cooling

Requirement)

High thermal expansion levels of

material used

Increase in surface temperatures

Increase in absorbtion of solar

radiation

Choice of dark colour

Local loads

Plate expansion restricted at the

edges

Stiffners are rigid

Connected to other stiffners and frames

Global loads

Hydrostatic loads cause primary

stresses

Primary stresses induce secondary

and tertiary stresses in the frames and

plating.

Region between bulkheads behaves

like simply supported beams

Region between bulkheads has low

stiffness

Bulkheads stiffer than frames

Functional Analysis

Root-Cause Analysis

Solutions for reducing high temperatures and deformations

Increase web height of frames and stiffeners in region between bulkheads

Reduce spacing between longitudinal stiffeners in region between bulkheads

Reduce porthole-hull area ratio

Low Solar Absorption (LSA) paints reflect IR light but not visible light

Use silver grey instead of dark grey (more reflective)

Climate Controlled Chamberes

Vinyl Paints

Remove yacht from water when not in use and/or store in covered garage

Align yacht with East-West direction so the sun hits only the bow or stern regions and not the hull directly.


Define ‘beauty’ objectively on a project-by-project basis

Defectometry


12-point appearance evaluation system ISO draft

standard TC 8/ SC 12 and BIS 11347

Solutions for improving/assessing hull coatings

Solutions for improving Energy Efficiency

Benchmark similar ships of different colours (energy use / fuel consumed…)

Reduce porthole-hull area ratio

Optimum balance between air conditioner size and insulation thickness

Reuse waste heat energy from the engine

Update old electrical equipment and wiring systems

Separation of HVAC systems such that different areas of the ship are cooled differently

Minimize impact of heat generating devices by using heat shields


Mode shapes due to load coupling (qualitative)


Only Structural

Thermal + Structural

54 ºC

12 ºC

Detailed FEM for Ship Scale Thermal-Structural Analysis


MSC SINDA 2013 with the Environmental Module Temperature only deflections in a ship section

Structural only deflections in a ship section

Conclusion

▪ From this this project, temperature variations of any metallic hulled ship can be analysed, anywhere in the world.

▪ Colour plays the most important role in deciding surface temperatures, followed by material and stiffness of the structure for deciding structural responses

▪ Port and starboard are asymmetrically exposed to solar radiation with a thermal gradient from bulwark to waterline, and from bow to stern

▪ Complex nature of ship structures - each part of the structure exercises some restraint or contraction on adjacent structures.

▪ Thermal and structural stresses interact, with material properties changing with temperature

▪ Yachts typically spend a majority of their time docked at the marina


Questions ?

VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 36 [email protected]

[email protected]

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