oil sea harvester project osh design : hydrodynamics and optimisation

OSH PMC MEETING N°7 9 th June 2006, Athens (GR)

OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Oil Sea Harvester Project

OSH design : Hydrodynamics and Optimisation

Partners involved :• CAT Shipyard (FR) : Design• BEC hydrodynamic laboratory (FR) : Numerical optimisation• CEHIPAR hydrodynamic laboratory (SP) : Test campaigns


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

General Objective :Optimisation of the operational

performances of the OSH concept

• Transit phase– Powering performances : relatively high transit speed

– Sea-keeping behaviour : low dynamic responses

• Oil recovery Phase– Sea-keeping behaviour for oil recovery operations up to sea state

6/7


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Transit phase : powering optimisation

• Objective :– Light displacement (8000 t)– Minimise the ship resistance at 25 knots– Minimise all hydrodynamic interactions

at medium speeds

• Constraints :– Pods integration (immersion of the transom stern)– central cylindrical part of the main hull not modified– Lateral distance between the side hull and the main hull not modified (toll carriage

and oil recovery tool integration)

• Design parameters :– Main hull– Side hull

Resistance

10 15 20 25 30Speed [kt]


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Powering optimisation : Main hull modifications

• Bow sections : thinner waterline

• Buttock line and transom immersion

• Bulbous bow

Initial

FinalOptimal

Initial Final

Initial

Final

Initial form


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Powering optimisation : Side hull modifications

• Best length : 101m (initial)

• Best longitudinal location : fore

80 m

101 m

138 m

120 m

Main hull

Side hull

Initialside hull

AP FP

Best compromise between bow wave interactionsand stern wave interactions

0.0E+00

5.0E+05

1.0E+06

1.5E+06

2.0E+06

12 14 16 18 20 22 24 26 28

Speed [kt]

Res

ista

nce

[N

]

Avant

-10

-20

Arrière

19 knots 25 knots

Fore

Aft


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Sea-keeping optimisation• Objective : sea-keeping performances

– Transit phase :V ≈20 knots - = 8 000 t Tool carriage in folded position

– Oil recovery operations :V : low speed = 12 000 tTool carriage deployed

• Constraints :– Pods integration– cylindrical part of the main hull not modified– distance between the side hull and the main hullnot modified (tool carriage integration)

• Design parameters :– Side hull– Tool carriage


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Seakeeping optimisation for oil recovery operations (Transit phase not critical)

• Increase of the side hull diameter : 3.5m (instead of 3m)

• No influence of the longitudinal position of the side hulls

• Optimal length of the tool carriage : 11.5m

• Optimal location of the tool carriage : middle of the side hull

0%10%20%30%40%50%60%70%80%90%

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8 m

11.5 m

15 m

18 m

Following waves (0°)

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aves

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eam starb

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waves (90°)

Head waves (180°)

Example of results :

Influence of the length of the tool carriage

on the oil recovery performances

Operability diagram for 4 lengths :

operability index (0-100%) versus wave heading


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

0%10%20%30%40%50%60%70%80%90%

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Initial

Optimal


Bea

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aves

(27

0°) B

eam starb

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waves (90°)

Head waves (180°)

Optimal design• Thinner bow sections

• Maximum transom immersion

• (Bulbous bow)

• Side hulls of length 101m at extreme fore location

• Tool carriage of length 11.5m located in the middle of the side hull


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Tank tests in progress (task 5.3)- assessment of the design optimised numerically- calibration of the numerical tools (re-used for the final design stage)

• Resistance tests almost completed– Great importance of the static trim

(transom immersion)

– Optimal location of the side hull : fore

Ship resistance (model)

0

5

10

15

20

25

30

0.0 0.5 1.0 1.5 2.0 2.5 3.0Speed [m/s]

Res

ista

nce

[kg

]

Trim 0m

Trim 2m

Trim 4m

Ship resistance (model)

0

5

10

15

20

25

30

0.0 0.5 1.0 1.5 2.0 2.5 3.0Speed [m/s]

Res

ista

nce

[kg

]

Fore position

5m aft

10m aft

Influence of the static trim

Influence of the longitudinal Side hull location

• Seakeeping tests carried out from June to September 06


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Thank you for your attention


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Seakeeping optimisation

• Definition of the operability value

• Transit phase– Roll < 12°

– Pitch < 4.5°

– Vertical acceleration < 3m/s²

• Oil recovery operations– Wave elevation < 1m

– Relative heave < 3m

– Vertical acceleration < 3m/s²

• Maximum significant height

• Operability diagramm

>14 0.0 0.0 0.1 0.2 0.2 0.1 0.1 0.0

13-14 0.0 0.0 0.1 0.1 0.1 0.1 0.0 0.0

12-13 0.0 0.1 0.1 0.2 0.2 0.1 0.0 0.0

11-12 0.0 0.0 0.1 0.2 0.3 0.3 0.2 0.1 0.0

10-11 0.0 0.0 0.2 0.4 0.5 0.4 0.2 0.1 0.0

9-10 0.0 0.1 0.4 0.8 1.0 0.7 0.4 0.1 0.0

8-9 0.0 0.2 0.8 1.6 1.7 1.2 0.6 0.2 0.1

7-8 0.0 0.4 1.8 3.2 3.1 2.0 0.9 0.3 0.1

6-7 0.0 0.1 1.1 4.0 6.5 5.8 3.4 1.5 0.5 0.1

5-6 0.0 0.3 2.9 9.3 13.3 10.7 5.7 2.2 0.7 0.2

4-5 0.0 1.0 7.9 21.3 26.3 18.5 8.7 3.0 0.8 0.2

3-4 0.1 3.2 20.8 45.6 46.9 28.0 11.3 3.4 0.8 0.2

2-3 0.0 0.5 10.3 48.9 81.6 65.6 31.5 10.4 2.6 0.5 0.1

1-2 0.0 2.2 28.5 84.3 93.4 52.4 18.2 4.5 0.9 0.1 0.0

0-1 0.4 8.9 34.1 43.3 24.8 7.9 1.7 0.3 0.0 0.0

<4 4-5 5-6 6-7 7-8 8-9 9-10 10-11 11-12 12-13 >13Zero crossing period (s)

Sig

nif

ican

t w

ave

hei

gh

t (m

)

SS 7

SS 8

SS 6

SS 5

SS 4

PilRel RelWave Zacc

Statistiques du Golfe de Gascogne

71.8%

0%10%20%30%40%50%60%70%80%90%

100%Relative wave

Relative waveRelative wave

Relative wave

Relative heave

Relative heave

Relative heave

Relative heave

Relative wave

Relative wave



Relative heave

Relative heave

Relative heave

Vertical acceleration




Relative heave



Bea

m p

ort

said

e w

aves

(27

0°) B

eam starb

oard

waves (90°)

Head waves (180°)

Quantity of oil spilled (tonnes) :

50 to 500

500 to 10 000

> 10 000


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Seakeeping optimisation Transit phase

• Better performances than in oil recovery operations

• No need to optimise

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Oil recovery

Transit


Bea

m p

ort

said

e w

aves

(27

0°) B

eam starb

oard

waves (90°)

Head waves (180°)


OIL SEA HARVESTER

TST4-CT-2004-516230

www.osh-project.org

Seakeeping optimisation Oil recovery operations

• Increase of the side hull diameter :3.5m

• No influence of the longitudinal position of the side hulls

• Optimal length of the tool carriage : 11.5m

• Optimal location of the tool carriage : middle if the side hull

0%10%20%30%40%50%60%70%80%90%

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210195

8 m

11.5 m

15 m

18 m


Bea

m p

ort

said

e w

aves

(27

0°) B

eam starb

oard

waves (90°)

Head waves (180°)

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-16 m-8 mInitial+10 m+20 m

Following waves (0°)B

eam

po

rtsa

ide

wav

es (

270°

) Beam

starbo

ard w

aves (90°)

Head waves (180°)

Lngitudinal location of the side hullsLength of the tool carriage

oil sea harvester project osh design : hydrodynamics and optimisation

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