2005 EDF R&D1

Code coupling for simulation

of flow-induced vibrations

Elisabeth LONGATTEFabien HUVELINMhamed SOULI

2 2005

FRAMEWORK

ASTER SATURNE

END

COMPUTATIONCOMPUTATION

END

DISPLACEMENT

LOADING

3 2005

FRAMEWORK

END

LOADINGCOMPUTATIONCOMPUTATION

END

DISPLACEMENT

LOADING

ASTER SATURNE

4 2005

FRAMEWORK

No

END

Si T > Tfinal

SUPERVISOR

Conditions on time step

Conditions on sub-cycling

ConvergenceTest

LOADING

DISPLACEMENT

DISPLACEMENT

No

END

LOADING

COMPUTATIONCOMPUTATION

IF SUB-CYCLING

IF SUBCYCLING

T=T + DT T=T + DT

Si T > Tfinal

DISPLACEMENT

LOADING

COSMETHYC ASTER SATURNE

5 2005

CODE_SATURNE

Code_Saturne

CFD Code developed by EDF R&D

• Two- and three-dimensional calculations of steady or transient single-phase, incompressible, laminar or turbulent flows

· Finite volume approach· Fully co-located arrangement of all variables· Time discretization based on a predictor-

corrector scheme· Any kind of mesh (hybrid, any type of cell)· RANS model, LES· ALE formulation (moving boundary)

6 2005

CODE_ASTER

Code_Aster

CSD Code developed by EDF R&D

• Linear, non linear statics• Linear, non linear dynamics

· Finite element method

· Time calculation (Newmark…)· Modal calculation (Newmark, Euler…)· Stochastic approaches· Dynamic response under loading

7 2005

COSMETHYC

Cosmethyc

CFSD Code developed by EDF R&D

• Fluid loading• Structure velocity

· Iterative procedure

SATAST

LOADING

Code_Aster

Code_Saturne

ASTSAT

VELOCITY

VELOCITY LOADING

8 2005

COUPLING PROCESS

Initialization

Statics computation

Fluid solver

Structure solver

Fluid solver

Transient computation

Fluid solver Structure solver

Time step loop

Coupling

Coupling

Coupling

End

9 2005

DATA TRANSFER

Data transfer operators

Interface

• Inlet, outlet data interpolation• Data projection

· 2D, 3D / 1D beam, 2D, 3D

nfns

fusu

10 2005

Non-matching interface

Aster mesh

Saturne mesh

Mesh interface

INTERPOLATION

11 2005

Code_Saturne

Code_Aster

SUPERVISOR

LOADING

CONVERGENCE

VELOCITY

SUPERVISOR

Supervisor

Coupling scheme

• Governs time iteration• Governs coupling scheme

· Prediction – correction on loading (convergence test)· Sub-cycling (implicit)

12 2005

COUPLING SCHEMES

Explicit synchronous schemePrediction of the fluid mesh motion Boundary conditions on the fluid-structure interface :

Fluid solver force computation (Fn)

Structure solver displacement computation (Un+1 )

UUtUtUXnnnnn

pred 1

10

1

time

ste

p

Explicit staggered schemePrediction of the fluid mesh motion Boundary conditions on the fluid-structure interface :

Fluid solver force computation (Fn+1/2)

Structure solver displacement computation (Un+1 )

Ut

UXnnn

pred

22/1

time

ste

p

(Farhat et al., 1995, 1997; Piperno et al., 1995,1997)

13 2005

COUPLING SCHEMES

Implicit scheme

Initialization :

Fluid solver force computation :

Structure solver displacement computation :

Fluid mesh motion :

Convergence criterion on the force values :

time

ste

p

Sub

-cyc

ling

UFXFnnknkn

,,,1,1

UFXUnknknkn

,,,1,1,1

UFXXknknknkn ,1,1,11,1

,,

F

FFkn

knkn

,1

1,1,1

Xn 0,1

14 2005

UKUKdtUdM sss 212

1

2

1

UKUKdtUdM sss 122

2

2

2

)sin()(1 tAtU

)(2)( 12 tUtU

MK ss 11

/3

)0(2)0( 12 UU

)0(2)0( 12

dtdU

dtdU

2/12

MM ss

COUPLING SCHEMES

1D test case

Error calculation / theory (-) f(-) x (-)

Explicit synchronous 0,0 8,0 10-4

Explicit asynchronous 0,0 7,0 10 -6

Implicit 0,0 9,0 10 –12

Strong coupling 0,0 7,0 10-12

Analytical 0,0 0,0

15 2005

VALIDATIONS

Concentric tubes

Dimensionless added mass in terms of diameter ratio

0,1

1

10

1 10

Diameter ratio D0/D

Dim

en

sio

nle

ss

a

dd

ed

ma

ss

Cm

St=100St=INFSt=5000 (theorique)St=10St=5000

Dimensionless added damping in terms of diameter ratio

0,01

0,1

1

10

1 10

Diameter ratio D0/D

Dim

en

sio

nle

ss

a

dd

ed

da

mp

ing

Cv

St=5000 (theorique)St=10St=100St=5000

16 2005

VALIDATIONS

Eccentric tubes

Dimensionless added mass and damping in terms of eccentricity

0,1

1

10

0 0,1 0,2 0,3 0,4 0,5 0,6 0,7

Eccentricity e

Dim

en

sio

nle

ss

pa

ram

ete

rs C

m,

Cv

/(R

HO

*PI*

R^

2*W

)

Cm

Cv/(RHO*PI*R^2*W)

Cm (MEF Chen)Cv (MEF Chen)

17 2005

VALIDATIONS

Tube bundles

Experimental Analytical Numerical

Frequency (Hz)

- 20.3 20.5

Damping (Hz) 0.037 ± 0.004

0.037 0.036

18 2005

V<Vc

V~Vc

V>Vc

VALIDATIONS

Tube bundles

19 2005

APPLICATIONS

20 2005

APPLICATIONS

21 2005

APPLICATIONS

22 2005

PARALLEL

Parallel code for distributed memory machines

PERSPECTIVES

23 2005

Domain partitioning

ALE

• Nodes

Coupling

• Data transfer operators

Wi

PARALLEL

PERSPECTIVES

24 2005

PERSPECTIVES

CONTACT

25 2005

PERSPECTIVES

CONTACT

26 2005

PERSPECTIVES

CONTACT

27 2005

PERSPECTIVES

CONTACT

28 2005

SALOMESUPERVISOR : To build schemes et control calculations –(with graphics)

Node = component (fluid, mechanics, thermics)Port = inlet / outlet parameters to and from nodesLink = connexion between ports Checking data types

PERSPECTIVES