s2p4 lret coe at pnu-hydrodynamics

7/27/2019 S2P4 LRET CoE at PNU-Hydrodynamics

1/73

at Pusan National UniversityProf. Jeom Kee Paik

Pusan National University

Jung Kwan Seo and Jeom Kee Paik

The Llo ds Re ister Educational Trust LRET

Marine & Offshore Research Workshop

16-18 February, 2010 at Engineering Auditorium, NUS


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LRET Marine & Offshore Research Workshop16-18 February 2010, The National University of Singapore

LRET Research Centre of ExcellenceLRET Research Centre of Excellenceatat PusanPusan National UniversityNational University

Prof.Prof. JeomJeom KeeKee Paik, DirectorPaik, Director


3/73

--

PartPart 11:: PlenaryPlenary byby ProfProf.. JJ..KK.. PaikPaik (Director)(Director)

.. .. ..

PartPart 33:: StructuresStructures 11 byby DD..KK.. KimKim (Graduate(Graduate Student)Student)

PartPart 44:: StructuresStructures 22 byby JJ..MM.. SohnSohn (Graduate(Graduate Student)Student)


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arar verv ewverv ew

StaffStaff LRETLRET ResearchResearch CentreCentre atat PNUPNU

BackgroundBackground NonlinearNonlinear StructuralStructural MechanicsMechanics

andand DesignDesign associatedassociated withwith LimitLimit StatesStates andand

ss asease e o se o s

OnOn-- oinoin ResearchResearch To icsTo ics


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aa esearc en re o xce ence,esearc en re o xce ence,


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ac esac es esearc en re o xce ence,esearc en re o xce ence,No. Equipment Name Specification Remark

1 Universal Test Machine (UTM) 1,000kN

, , .

3Dynamic loading actuator

500kN, Stroke 500mm, Max. speed 0.2m/s

4 Impact loading actuator 1,000kN, Stroke 1,000mm, Max. speed 20m/s

5 2,000kN, Stroke 500mm-

6 5,000kN, Stroke 500mm

7-192C ~ 200C,

Max. model size 400 400 600mm (inside)

8

Low temperature chamber-170C ~ 100C,

.

9 High temperature chamber 20C ~ 700C,Max. model size 1000mm 2000mm 2000mm (inside)

9 Cannon type, Max. speed 30m/s

Dropped object

10 Free fall type, Height 4.5m

11 ANSYS Nonlinear finite element method (quasi-static)

12 LS-DYNA Nonlinear finite element method (Dynamic/impact)

14 MAESTRO Robust ship structural design

15 ALPS Intelligent super-size finite element method

16 Kameleon FireEx (KFX) CFD code for fire analysis

17 FLACS CFD code for gas dispersion and explosion analysis

18 USFOS Nonlinear structural consequence analysis under fire

19 NEPTUNE Qualitative risk calculations


7/73

ac grounac groun on near ruc ura ec an cs an es gnon near ruc ura ec an cs an es gn


8/73

ac grounac groun on near ruc ura ec an cs an es gnon near ruc ura ec an cs an es gn


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International Journal EditorshipInternational Journal Editorship

International Journals Role

Shi s and Offshore Structures Ta lor & Francis UK 32 a ers Editor-in-Chief

ummary o c v es ur ngummary o c v es ur ng

Structural Longevity, Tech Science Press, USA (4 papers) Editor-in-Chief

Ocean Engineering, Computer Modeling in Engineering and Sciences, International Journal

of Impact Engineering, Journal of Marine Science and Technology, International Journal ofMaritime Engineering, Journal of Engineering for the Maritime Environment, Institute of Associate EditorEditorial Board ,

Book Chapters (ComputerBook Chapters (Computer--Based Ship Structural Design: Theory and Practice, SNAME)Based Ship Structural Design: Theory and Practice, SNAME)

Chapter Title Author

Jeom Kee Paik

10 Deformation and Strength Criteria for Stiffened Panels under Impact Pressure

12 Elastic Buckling of Plates

13 Large Deflection Behaviour and Ultimate Strength of Plates

International Conferences OrganizedInternational Conferences Organized

15 Large Deflection Behaviour and Ultimate Strength of Stiffened Panels

16 Ultimate Strength of Ship Hulls

n erna ona on erences o e

International Conference on Computational and Experimental Engineering and Sciences(ICCES), 28 March -1 April 2010, Las Vegas, USA

Paper presentations, Keynotespeaker Symposium organizer

International Conference on Ocean, Offshore, and Arctic Engineering (OMAE), 6-7 June2010 Shan hai China

Paper presentations, Keynotes eaker S m osium or anizer

International Conference on Computational and Experimental Engineering and Sciences

(ICCES), Special Symposium on Meshless and Other Novel Computational Methods, 17-21 August 2010, Busan, Korea

Paper presentations, Keynotespeaker, Conference organizer


11/73

--


12/73

esearc op csesearc op cs11.. MechanicalMechanical PropertiesProperties ofof VariousVarious MaterialsMaterials inin BothBoth ColdCold andand

ElevatedElevated TemperaturesTemperatures

22.. NonlinearNonlinear FiniteFinite ElementElement AnalysisAnalysis

3. Tank Sloshing Impact Design of Membrane-Type LNG Carriers

4. Ice Class Ship Structural Design

55.. FireFire RiskRisk AssessmentAssessment andand ManagementManagement ofof OffshoreOffshore InstallationsInstallations

66.. GasGas ExplosionExplosion AssessmentAssessment andand ManagementManagement ofof OffshoreOffshore InstallationsInstallations

.. rogress verogress ve a urea ure na ys sna ys s oror nt rent re pp tructurestructures

88.. SandwichSandwich PlatePlate SystemSystem (SPS)(SPS) DesignDesign

.. ua yua y ssurancessurance oo oo -- orm ngorm ng rocessrocess oo reeree-- mens ona ymens ona y

CurvedCurved MetalMetal PlatesPlates usingusing ChangeableChangeable DieDie SystemSystem

..

1111..


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1. Mechanical Pro erties1. Mechanical Pro erties

of Various Materials in Both Coldof Various Materials in Both Cold

and Elevated Tem eraturesand Elevated Tem eratures


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Mild / high tensile steel (with different grades), aluminum alloy, stainless steel,

foam, elastomer

Temperatures, , ,

Quasistatic, dynamic / impact

rate

Database

Mechanical properties (elastic modulus, yield stress, ultimate tensile stress,

, ,

Minimum Requirements


15/73

Longitudinal edge

edge

Longitu

Longitudinal edge


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Nonlinear FEA

Extreme loads

Large deformation / small strain-

Accidental loads

Large deformation / large strain-,

Plasticity

Fracture

Plasticity

Modeling Techniques Modeling Techniques

Extent of anal sis Mesh size

Mesh size

Material model

Initial imperfections

True stresstrue strain relation

Dynamic yield stress

Dynamic fracture strain

Boundary condition

Loading condition

Dynamic / impact load profile

Applied Examples and Verifications


17/73

1400

160016C

Abramowicz-Jones formula: 372.7kNTest: 404.5kN

Mean crushing strength (Pmean)

1000

1200

kN)

FEA: 383.6kN

600

800

For

ce Test

First fracture

0

200

0 50 100 150 200 250 300 350 400

Indentation(mm)


18/73

3. Tank Sloshing Impact Design3. Tank Sloshing Impact Design

yz

yz

S mmetric conditionS mmetric condition

xx Ux=0, Roty=0, Rotz=0

Uy=0, Rotx=0, Rotz=0

Ux=0, Roty=0, Rotz=0

Uy=0, Rotx=0, Rotz=0


19/73

an os ng es gn

Design Loads Structural Failure Analysis

Fracture of corrugated membrane

Fracture of insulation system (foam)

Modeling

Extent of analysisSloshing

Frequency

Sloshing Scenarios

Tank filling level

Duration of tank motion

Mesh size (corrugation, foam)

True stresstrue strain relation in cryogeniccondition

Dynamic yield stress

Rolling angle

Sea Dynamic fracture strain

Mastic

Sloshing load profile

mu a ons

SloshingLoad Characteristics

Trials

os ng oa pro e w t t me

Peak pressure

Pressure impulseFirstFracture Based Structural

Design Curve

Design Sloshing Loads

Probabilistic exceedance curve


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4. Ice Class Ship Structural Design4. Ice Class Ship Structural Design


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Initial scantling

Internal Mechanics

Initial scantling

Initial scantling

Internal Mechanics

External mechanics

Initial kinetic energy (Ei)

Energy absorption of both ship and iceberg

Collision Scenarios

Iceberg size

External mechanics

Initial kinetic energy (Ei)

Energy absorption of both ship and iceberg

Collision Scenarios

Iceberg size

Iceberg draft

Iceberg material (age)

Ship type and size

Ship draft

Iceberg draft

Iceberg material (age)

Ship type and size

Ship draft

Collision location

Collision angle

Collision speed

Collision location

Collision angle

Collision speed

Structural Crashworthiness Analysis

Reaction force indendation relation for

iceber



shi structuresAA BB



iceber



shi structuresAA BB Absorbed energy ( ) Absorbed energy ( )

E E + ENo

Eas Eai Absorbed energy ( ) Absorbed energy ( )

E E + ENo

Eas Eai

as a

stop

Yes

as a

stop

Yes


22/73

Modeling for Nonlinear FEA of Ship

Mesh t e and size steel

Engineering stressengineering strain relation

True stresstrue strain relation

Knockdown factor for true stresstrue strain relation

Fracture strain used for nonlinear FEA

Dynamic yield strain (strainrate effect)

Dynamic fracture strain (strainrate effect)

Extended true stresstrue strain relation

Modeling for Nonlinear FEA of Iceberg

B

Mes type an s ze ( ce erg

Engineering stressengineering strain relation (test database)

True stresstrue strain relation (test database)

ec o s ra nra e on ynam c y e s ress es a a ase

Effect of strainrate on fracture strain (test database)


23/73

1600

Abramowicz-Jones formula: 400.6kN

-40C Mean crushing strength (Pmean

)

1000

1200

N)

Test: 473.8kN

FEA: 430.7kN

600

800

Forc

e(k FEA

TestFirst fracture

0

200

0 50 100 150 200 250 300 350 400

Indentation(mm)


24/73

5. Quantitative Fire Risk Assessment and5. Quantitative Fire Risk Assessment and

ManagementManagement


25/73

uan a ve re s ssessmen an anagemen

Fire Frequency

= Leak frequency x ignition probability

Fire Scenarios

Wind direction (X1)

Wind speed (X2) Leak rate X

Leak duration (X4)

Leak direction (X5)

Leak position X (X6)

Leak osition Y X

Nonlinear Structural Consequence Analysis

Leak position Z (X8)

Risk = Fire frequency x consequence

CFD simulations

Fire Load Characteristics

Fire load profile with time

RiskALARP stop

Yes

No

empera ure

Heat doseRisk Control Option Design

Fire wall

Passive fire protection (PFP)

Probabilistic exceedance curve Deluge / water spray


26/73


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6. Quantitative Gas Explosion Risk Assessment6. Quantitative Gas Explosion Risk Assessment

and Managementand Management


28/73

xp os on requency

= Leak frequency x ignition probabilityExplosion Scenarios

Wind direction (X1)

Wind speed (X2)

Leak rate (X3)

Leak duration (X4)

Leak direction (X5)

Leak position X (X6)

Leak position Y (X7)

Gas Explosion Load Characteristics

Explosion load profile with time

Leak position Z (X8) ast pressure

Pressure impulse

Gas Dispersion AnalysisDesign Gas Explosion Loads

Gas Cloud Characteristics

Gas volume (Y1)

Gas concentration (Y2)

Nonlinear Structural Consequence Analysis

=

Gas cloud position X (Y3)

Gas cloud position Y (Y4)

Gas cloud position Z (Y5)

Gas cloud size X (Y6)

RiskALARP stopNo

Gas c ou s ze Y Y7 Gas cloud size Z (Y

8)

Risk Control Option Design Blast wall

Yes


29/73


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Coarse meshglobal NLFEA 0.6

0.7

0.2

0.3

0.4

0.5

PR

ESSURE

[N/mm2]

Medium mesh

0 20 40 60 80 1000

0.1

DISPLACEMENT [mm]

Experiment Analysis

Laboratory experiments wit h

subassemblymodel

Out-of modelcomponent checkusing fine mesh

NLFEA


31/73

PressurePressure


32/73

of Entire Ship Structuresof Entire Ship Structures


33/73

rogress ve a ure na ys s or n re p ruc ures

New Algorithm

Intelligent Supersize Finite Element

Method (ISFEM)

Experiment

Intelligent Supersize Finite ElementsModel Tests

Beancolumn element

Plate element

3dimensional algorithm

Stiffened panels (stiffened box) Hulls (box girders)

Large scale ship sturcture models uc ng an co apse

Plasticity

Crushing / folding

Strainrate sensitivity

Finite Element

Method

Applied Examples and Validations


34/73

Under vertical bending

rogress ve o apse na ys s o p u srogress ve o apse na ys s o p u s

t(GNm)

5.0

10.0

15.0

Muhog_CSR

=11.049GNm

Muhog_FEA(CSR)

=9.654GNm

Muhog_HULL(Pre-CSR)

=8.557GNm

Muhog_HULL(CSR

=9.465GNm)

-

14

16 CSR design

seline(m)

Hogging

Net

Ve

rticalbendingmomen

-5.0

0.0Hog

Sag

Musag_HULL(Pre-CSR)= 7.694GNm

Musag_req.7.686GNm

Muhog_req.=5.768GNm

-5.0

0.0

Musag_HULL(Pre-CSR)= -

=-

.

8

10

12

to

neutralaxisfromb

50%

As-built

As-built

-4.0 -2.0 0.0 2.0 4.0

-15.0

-10.0

Musag_CSR

=-8.540GNm

usag_HULL(CSR= -8.329GNm

Musag_FEA(CSR)

= 8.107GNm

Nonlinear FEA (ANSYS)

: CSR design deducting 50% corrosion additions

ALPS/HULL

: CSR design deducting 50% corrosion additions

: Pre-CSR design deducting 100% corrosion additions

- -

-15.0

-10.0

=-

M )

)= -

Nonlinear FEA (ANSYS):

- CSR design deducting 50% corrosion additions

ALPS/HULL:

- CSR design deducting 50% corrosion additions

-Pre --CSR design deducting 100% corrosion additions

-40 0.5 1.0 1.5 2.0 2.5 3.0

4

6

ULS

Curvature10 (1/m)

Height

SaggingNet

3333 Ultimate Strength (lll.1)

Change of neutral axis posit ion


35/73

Under combined hull girder actions

rogress ve o apse na ys s o p u srogress ve o apse na ys s o p u s

z

MH

Between Trans. frames

yFH

FV

MV

xMT

p

3434 Ultimate Strength (lll.1)

e ween rans. u ea s


36/73


37/73

SPS Design

Governing Differential

Equations

Model Test

Tensile test of material

Modeling Techniques

Mesh size

na y ca e o on near xper men

Buckling strength formula

Ultimate strength formula

Buckling strength test

Ultimate strength test

Material modeling

Boundary condition Loading condition

Comparison

Guidance and Rule Requirements


38/73

. ua ty ssurance o o. ua ty ssurance o o -- orm ng rocessorm ng rocess

of 3D Curved Metal Platesof 3D Curved Metal Platesus ng angea e e ystemus ng angea e e ystem


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Quality Assurance of Cold forming Process

of 3D Curved Metal Plates using Changeable Die System

New Algorithm

Springback calculation algorithm

Experiments

Changeable die system developmentusing nonlinear structural mechanics (Prototype)

Pressing punch strength tests

Cold-forming tests

Analysis of Spring-back Behavior(Nonlinear FEA)

Material tests (plates)

Material properties

Pressing punch geometry

Applied Examples and

Validations

CAM System

Quality Assurance Recommendations

Pressing punch control


40/73

10. Condition Assessment of A ed Structures10. Condition Assessment of A ed Structures


41/73

Condition Assessment of Aged Structures

Timevariant Fatigue Cracking ModelTimevariant Fatigue Cracking ModelTimevariant Corrosion ModelTimevariant Corrosion Model

Ultimate Strength Model Experiment

(Residual Strength)

Analytical model

Numerical model

Buckling

Plastic collapse

Reliabilitybased Assessmentand Management

Guidance and RecommendationsGuidance and Recommendations


42/73

Fire and ExplosionFire and Explosion

LRET Research Centre of Excellence

at Pusan National University

HydrodynamicsLRET Marine & Offshore Research WorkshopLRET Marine & Offshore Research Workshop

1616--18 February, 201018 February, 2010

Jung KwanJung Kwan SeoSeo andand JeomJeom KeeKee PaikPaik


43/73

z Validation and verification of CFD Simulations

z Fire Load Characteristics

z Thermal Diffusion Analysis

Overview

I.I. BackgroundsBackgrounds

II.II. Aims and ScopeAims and Scope

III.III. Fire EngineeringFire Engineering

IV.IV. Explosion EngineeringExplosion Engineering

V.V. OnOn--going Studiesgoing Studies

z CFD Simulations


44/73

BackgroundsBackgrounds

{{ Piper alpha(1998),Piper alpha(1998), EnchovaEnchova central offshore(1998)central offshore(1998)

{{ Fire and explosion caused by gas and oil leakageFire and explosion caused by gas and oil leakage

{{ API(AmericanAPI(American Petroleum Institute), DOE (Department of Energy),Petroleum Institute), DOE (Department of Energy),

NPD(NorwegianNPD(Norwegian PetroleumPetroleum DirektorareDirektorare), Lloyds rules), Lloyds rules

Piper alpha accidentPiper alpha accident EnchovaEnchova central offshore accidentcentral offshore accident


45/73

Aims and ScopeAims and Scope

zz DevelopingDeveloping Quantitative Fire & Explosion Risk AssessmentsQuantitative Fire & Explosion Risk Assessments

procedureprocedure

zz Establishing a procedure for defining design actions based onEstablishing a procedure for defining design actions based on

CFD simulations forCFD simulations for FPSOsFPSOs

zz Developing deterministic and probabilistic methodologies forDeveloping deterministic and probabilistic methodologies for

the analysis of fire and gas explosion actions using modern CFDthe analysis of fire and gas explosion actions using modern CFD

codescodes


46/73

Phase I: Fire EngineeringPhase I: Fire EngineeringCFD SimulationsCFD Simulations

Validation and Verification of CFD Codes


47/73

Difference

Application

areas

Element

Program

All kind of fires

Fire impact

Mitigation

Combustion

Multiphase

Heat transfer

Radiation

Combustion

CFD Fire simulation toolMultipurpose simulation tool

GridTetrahedra, Prism

ANSYS-CFX Kameleon FireEx

The Discrete Transfer modelThe Discrete Transfer model(DTM)(DTM)

P1 modelP1 modelRadiationRadiation

ConductivityConductivityAdiabatic, Temperature andAdiabatic, Temperature and

Heat transfer coefficientHeat transfer coefficientWall heat transferWall heat transfer

PorosityPorosityTetrahedraTetrahedraSub grid geometrySub grid geometry

The Eddy Dissipation ConceptThe Eddy Dissipation Concept

(EDC) model(EDC) model

NoneNoneSootSoot

Kameleon FireEx methodANSYS CFX methodModeling

CFD SimulationsCFD Simulations

ANSYS-CFX and Kameleon FireEx (KFX)


48/73

Temperaturesensor

Propane gas (CHPropane gas (CH33CHCH22CHCH33) jet fire test) jet fire test

[Source: HSE 1995][Source: HSE 1995]

Nozzle

Propane gas

Fuel release rate: 0.33 kg/s

A

B

C

D

Air condition: O2 (21%),N2 (79%)

Thermally insulated plate

9.80m

2.00m

2.50m

3.54m

3.91m

Nozzle

Propane gas

Fuel release rate: 0.33kg/s

A

B

C

D Opening(ventilation)

Air condition: O2 (21%),N2 (79%)

Thermally insulated plate

9.80m

2.00m

2.50m

3.54m

3.91m

HSE Laboratory Test (Jet Fire)HSE Laboratory Test (Jet Fire)


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Heat transfer conditions of the wallHeat transfer conditions of the wall

0 2 4 6 8 10 12 14 16 18 20 22

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

0 2 4 6 8 10 12 14 16 18 20 22

0

200

400

600

800

1000

1200

1400

1600

1800

2000

2200

Time (s)

Temperatu

re(K)

AdiabaticWall heat transferwith heat transfercoefficient (30W/m2K)

Wall heat transfer withambient temperature of281K

A

B

C

D

9.80m

2.00m

2.50m

3.54m

3.91m

1.7m

1.7m

1.7m

A

B

C

D

9.80m

2.00m

2.50m

3.54m

3.91m

1.7m

1.7m

1.7m

A

B

C

D

9.80m

2.00m

2.50m

3.54m

3.91m

1.7m

1.7m

1.7m

Nozzle Opening

0.33Mass flow rate

(kg/s)

P1 modelRadiation

ThermalenergyHeat transfer

1.7Height (m)

Experiment

C-D (Height: 1.7m)

CFD Simulations (1/3)CFD Simulations (1/3)


50/73

0 1 2 3 4

0

200

400

600

800

1000

1200

1400

1600

CFXExperimentKFX (Conduct 1e-6W/m2K)

Height (m)

Temperat

ure

(K)

A-B

Results of CFX versusResults of CFX versus KFXKFX


0 1 2 3 4

0

200

400

600

800

1000

1200

1400

1600

Height (m)

Temperature

(K)

CFXExperimentKFX (Conduct 1e-6W/m2K)

C-D

A

B

C

D

9.80m

2.00m

2.50m

3.54m

3.91m

1.7m

1.7m

1.7m

A

B

C

D

9.80m

2.00m

2.50m

3.54m

3.91m

1.7m

1.7m

1.7m

A

B

C

D

9.80m

2.00m

2.50m

3.54m

3.91m

1.7m

1.7m

1.7m

Nozzle Opening


51/73

The result of CFD simulationsThe result of CFD simulations

ANSYS CFX (CFD) simulationANSYS CFX (CFD) simulation KameleonKameleon FireExFireEx simulationsimulation


Kameleon FireEx tends to have more accuracy and less

computing time than ANSYS CFX


52/73

Phase II: Fire EngineeringPhase II: Fire EngineeringFire Load CharacteristicsFire Load Characteristics

Concrete and steel tubular member


53/73

Jet fire test with concrete tubular member

Concrete

Temperature(K)

Temperature(K)

Temperature(K)

Time (s) Time (s) Time (s)

Steel

Temperature(K)

Temperature(K)

Temperature(K)

Time (s) Time (s) Time (s)

Jet fire test with steel tubular member

Fire Load Characteristics (1/5)Fire Load Characteristics (1/5)

Convection=

+Radiation

+Conduction

Convection=+

Radiation

+Conduction


54/73

Gas component: CH4: 100%, volume late: 20L/min

CH4 10L/min CH4 15L/min CH4 20L/min

C3 H8: 61.6%

N2: 30.2%

C4 H10: 8.2%

CH4: 88.9%

C2 H6: 8.9%

C3 H8: 1.3%

LPGLNG

Working pressure: 4bar, volume rate: 20L/min

CH4 100%Fuel fraction

300.2Ambient temperature

(K)

8Leak diameter (mm)

0.857Leak rate (g/sec)

V mPV

t RTt

=



55/73



56/73

12

3

5

4 6

7

8

12

3

5

4 6

7

8

Measurement points

AABB BB CCCC

200mm x 4200mm x 4

FireFire

directiondirection

1140mm1140mm

0 20 40 60 80 100

200

400

600

800

1000

1200

1400

Time(s)

Temperatu

re(K)

Section A1Section A1 Test(Concrete)Test(Steel)

Leak rate= 0.000857516kg/sec, Methane= 100%



57/73

Results at section A (average for 90~100s)

A-5

A-6

A-7

A-8

A-1

A-2

A-3

A-4

0 300 600 900 1200 Temperature(K)

CFD (KFX)CFD (CFX)Test(Concrete)Test(Steel outside)Test(Steel inside)

CFDCFDTestTestTest

12

3

5

4 6

7

8

12

3

5

4 6

7

8

Measurement points

AABB BB CCCC

200mm x 4200mm x 4

FireFire

directiondirection

1140mm1140mm



58/73

Phase III: Explosion EngineeringPhase III: Explosion EngineeringThermal Diffusion CharacteristicsThermal Diffusion Characteristics

To examine the effect of wind velocity and directionTo examine the effect of wind velocity and direction


59/73

h l Diff i Ch i i (2 6)Th l Diff i Ch i i (2/6)


60/73

Heat source

position

Wind

direction

Wind speed

(m/s)

Case1 A Rear1.5

2.0

Case2 A Side1.5

2.0

Case3 A Front1.5

2.0

Case4 B Front

1.5

2.0

Test CasesTest Cases

B AB A

Thermal Diffusion Characteristics (2/6)Thermal Diffusion Characteristics (2/6)

Side

Front

Rear

1 2 3

Th l Diff i Ch t i ti (3/6)Th l Diff i Ch t i ti (3/6)


61/73

A-R1 A-R2

1.5m/s 306.4 302.0

2.0m/s 303.4 301.1

SpeedSpeedPointsPoints

Temperature(KTemperature(K) (at t= 771 ~ 800s)) (at t= 771 ~ 800s)

A-R1

A-R2

0 200 400 600 800

Time(s)

296

298

300

302

304

306

308

Temperature(K)

Wind direction: Rear

Wind speed: 1.5m/s

A-R1

A-R2

0 200 400 600 800

Time(s)

296

298

300

302

304

306

308

Temperature(K)

Wind direction: Rear

Wind speed: 2.0m/s

A-R1

A-R2

Wind speed: 1.5m/s vs. 2.0m/sWind speed: 1.5m/s vs. 2.0m/s


Th l Diff i Ch t i ti (4/6)Th l Diff i Ch t i ti (4/6)


62/73

0 100 200 300 400 500 600 700

294

314

334

354

374

394

414

434

T

emperature(K)

Test(1.5m/s)

Test(2.0m/s)

A-S2

A-S3

A-S4

CFX(1.5m/s)

CFX(2.0m/s)

A-S2

A-S3

A-S4

A-S2

A-S3

A-S4

A-S2

A-S3

A-S4

1.5m/s1.5m/s

2.0m/s2.0m/s

Thermal diffusion characteristics (at t= 800s)Thermal diffusion characteristics (at t= 800s)

Distance from the center of heat source(mm)


Th l Diff i Ch t i ti (5/6)Thermal Diffusion Characteristics (5/6)


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Thermal diffusion characteristics (at t= 800s)Thermal diffusion characteristics (at t= 800s)

0 100 200 300 400 500 600 700 800

294

314

334

354

374

394

T

emperature(K)

A-R2 A-R3 A-R4

Test(1.5m/s)

Test(2.0m/s)

CFX(1.5m/s)

CFX(2.0m/s)

A-R2A-R3A-R4

A-R2A-R3A-R4

A-R2A-R3A-R4

1.5m/s1.5m/s

2.0m/s2.0m/sDistance from the center of heat source

(mm)




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Temperature distributionTemperature distribution Velocity distributionVelocity distribution

{{ Wind direction: RearWind direction: Rear

{{ Wind speed: 1.5m/sWind speed: 1.5m/s

{{ Location of heat source: ALocation of heat source: A

A-R2A-R3A-R4



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Phase IV: OnPhase IV: On--going Studiesgoing StudiesFPSOsFPSOs TopsideTopside

Fire Load CharacteristicsFire Load Characteristics


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KFX simulation

Wind direction:

+Y (5m/s)

y x

z




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2525 FWDFWD

2424

2323

2222

Elevation view Plan view at elevation A


Temperature distribution of elevation A

Total number of grids: 500,000, Leak rate: 48kg/sec

0.1 (s)0.1 (s) 1.0 (s)1.0 (s) 5.0 (s)5.0 (s) 10.0 (s)10.0 (s)

IP

57m

60m

AIP

64m

Elevation B

Elevation A

Gas Dispersion StudiesGas Dispersion Studies


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Totally 50 dispersion simulations were carried out.

The following parameters defined each leak scenario:

- wind direction

- wind speed

- leak direction

- leak rate- leak duration

- leak position X

- leak position Y

- leak position Z




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Shape of the big gas cloud (Leak rate: 50kg/s)

top viewfront view




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The model represents:

- main structural members of all modules

- bigger equipment items

- main pipelines

Geometry is supplemented by extra piping to achieve a

realistic congestion.

The FLACS model of the entire topside

Presence of surrounding topside structures

affects:

- wind flow pattern

- gas cloud build-up

- magnitude of explosion loads


Gas Cloud Characteristics StudiesGas Cloud Characteristics Studies


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Dispersion scenarios Cloud Position

Many of the gas clouds build up in adjacent modules.

Position of a gas cloud is determined mostly by the wind direction and to amuch smaller degree by leak direction.

Gas Cloud Characteristics StudiesGas Cloud Characteristics Studies

- Gas Volume, Gas Concentration

- Gas Cloud Position (X, Y, Z)

- Gas Cloud Size (X, Y, Z)

Design Gas Explosion LoadsDesign Gas Explosion Loads


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Design Gas Explosion LoadsDesign Gas Explosion Loads

Explosion load characteristics: peak over pressure (PMAX) versusduration (T+) based on CFD simulations.

Nonlinear Structural Consequence AnalysisNonlinear Structural Consequence Analysis


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Structural response in case of fire

Required PFP

Mitigate Consequences (Nonlinear Structural Mechanics)

FireFire

Nonlinear Structural Consequence AnalysisNo l ea St uctu al Co seque ce alys s

s2p4 lret coe at pnu-hydrodynamics

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