CFD Online Discussion Forums - diffusivity selection for modified displacementLaplacian solver for FSI problems

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diffusivity selection for modified displacementLaplacian solver for FSI problems

Hi, guys,

I have encountered a severe problem about dynamic mesh motion.

I used my modified displacementLaplacian Solver to couple with external software to deal with FSI multi-body motion problem. the settings in my dynamicMeshDict is as follows:

Code:

dynamicFvMesh      dynamicMotionSolverFvMesh;



motionSolverLibs ("libfvMotionSolvers.so");



solver           MBdisplacementLaplaciancouple;

 

MBdisplacementLaplaciancoupleCoeffs

{

  diffusivity   quadratic inverseDistance (wing1 wing2 wing3);

  patches1    (wing1);

  patches2    (wing2);

  patches3    (wing3);

  rhoName    rhoInf;

  rhoInf    1000;

}

I have got some questions to ask for my settings

1. how did diffusivity solver works? it solver for each patch one by one, or it solves all the patches at the same time?

2. I saw some case put the number 1 behind inverseDistance, what does that mean?

3. for the moving patches, I have set the BC as fixedValue in the pointDisplacement file, is that right. I have tried to use calculated BC but error occurred.

4. I have attached some images showing my incorrect mesh motion for internal mesh that caused wrong oriented faces near the patch. I guess that is because when I get all the patch data from external solver correctly, the internal mesh solved by OpenFOAM didnot move together correctly with the patch so the error appears as in the image. Dose it corresponding to any of my settings in the dynamicMeshDict?

Any help from any Foamer is much appreciated:D.

Hi dear zhao
could you find how to solve this issue?
I want to put 3 patches in diffusivity but i can't find how to fix it.
thank you

Quote:

Originally Posted by mobina (Post 625010)

Hi dear zhao
could you find how to solve this issue?
I want to put 3 patches in diffusivity but i can't find how to fix it.
thank you

Hi, mobina,

Do you want to put 3 patches into the laplacian solver that contains solving diffusivity or just want to put 3 patch names in the dynamicMeshDict?

If you want to put 3 patches in the dynamicMeshDict, Just do what I have written in the previous post. Don't put number '1' behind the inverseDistance as it can only be used when you have 1 patch.

Also, you need to lookup the patch name specified in dynamicMeshDict in your corresponding laplacianSolver, or maybe SBRStressSolver.

ZHENKAI