Post on 17-Apr-2018
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 ?
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 3
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 4
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 6
Longitudinal temperature variation
Vertical temperature variation
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 7
Port temperature variation Starboard temperature variation
Dark
-Blu
e S
hip
S
ilver
Gre
y S
hip
W
hite S
hip
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 8
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 9
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 10
1. Selection of the ASHRAE model
1. Practical to use
2. Available data
3. Well-established methods
Theoretical modelling
External Reference
2. Ship Geometry
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 11
Tilt Angle
Surface Azimuth Angle
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 12
3. Heat Transfers
𝑇𝑠4 𝜖𝜎𝐴 + 𝑇𝑠 ℎ𝑐𝐴 +
1
ℎ𝑠 − ℎ𝑤+
1
Roverall − 𝜖𝜎𝐴𝑇𝑠𝑘𝑦
4 + ℎ𝑐𝐴𝑇∞ +𝑇𝑠ℎ𝑖𝑝
Roverall+
𝑇𝑤ℎ𝑠 − ℎ𝑤
= 0
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 13
Parametric Analysis
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 14
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 15
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 16
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 17
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
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 18
-180 +90
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
-90
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 Ship Heading 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
-164
Effects of High Temperatures
▪ Hull Deformations
▪ Optical Distortion Effects
▪ Hull Coating Defects
▪ Increased Cooling Loads
▪ Internal Hull Surface Condensation
▪ Thermal Comfort
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 19
Deflections
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 20
DEFLECTIONS
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 21
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 22
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 23
Optical Distortion
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 24
F2F F' 2F'
virtual , upright & magnified imageobject
Heated Air
CoolerAir
deviation
Other Effects of Temperature
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 26
Fuel consumption variation with load
(DieselService&Supply, 2014)
Hull Coating Defects
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 27
Solutions and Implementations
TRIZ (Theory of Inventive Problem Solving)
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 28
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 29
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.
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 30
Define ‘beauty’ objectively on a project-by-project basis
Defectometry
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 31
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 32
Mode shapes due to load coupling (qualitative)
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 33
Only Structural
Thermal + Structural
54 ºC
12 ºC
Detailed FEM for Ship Scale Thermal-Structural Analysis
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 34
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
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 35
Questions ?
VIVEK KUMAR | EMSHIP 2012-2014 | University of Genoa | Baglietto Shipyards, Italy 36 vivek.kumar.mailbox@gmail.com
vivek.kumar.mailbox@gmail.com
37