[hchen]

Dear Foamers:

I use dynamic mesh to simulate flow around oscillating cylinders in foam extend 3.1. The dynamic mesh simply update the displacement of the cylinder and call the fvMotionSolver. It works fine in serial case, but for parallel execution, the mesh is moving in a strange way in between the processor boundary. I attached the figures below. The location where the unphysical moving mesh occurs is just in between the domains for processors. I am not sure this is due to the problem of my custom dynamic mesh class (although I do not think so) or other OpenFoam problems?

Best regards
Hao Chen

[hchen]

Hi again,,,

For some other cases, I found that the mesh in the processor boundary does not move at all. In the figure below, I impose a rigid body motion on the cylinder and also the mesh near the cylinder. The rest is moving with fvDisplacementLaplacian. However, the point in the boundary does not move at all. Any suggestions and comments are welcome.

[Ya_Squall2010]

I am having the same problem in running interDyMFoam using multiple CPUs. It even crashes when you run the accompanied floatingObject tutorial case in parallel. Have you identified the source of this problem? Thanks.

[hayder]

I am having the same problem in running fluent with dynamic mesh using parallel mode . Have you identified the source of this problem?
If Yes could you please send me some tips. Thanks in advance.

[Ya_Squall2010]

I'd like to know if anyone else is having this problem? Or is there a solution to it?

[hjasak]

Please use tet FEM automatic mesh motion solvers and all will be well.

Hrvoje

[hchen]

Yes I think FEM is much robuster than FVM for foam extend versions. Otherwise if you still want to use FVM dynamic mesh, you'd better change to openfoam official versions.

Best
Hao

[Ya_Squall2010]

The reason why I tried to switch to fvMotionSolver is that I'd like to compare the BiCGStab to GAMG, as sometimes the former is struggling in 3D cases, even 100+ subiterations are not enough for it to reach convergence.

[wangchengan2003]

Dear Jasak
I try to make parallization for the dynamic mesh problem by using the solver pimpleDyMFoam. The orginal case 'movingCone' works well under parallization process. But if "
dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solver velocityComponentLaplacian;

velocityComponentLaplacianCoeffs
{
component x;
diffusivity directional ( 1 200 0 );
}
" in the file 'dynamicMeshDict' is simplely changed as "
dynamicFvMesh movingConeTopoFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

movingConeTopoFvMeshCoeffs
{
motionVelAmplitude (1.5 0.0 0.0);
motionVelPeriod 0.003;
leftEdge 0.0;
leftObstacleEdge 0.0;
rightObstacleEdge 0.0;

right
{
minThickness 3e-5;
maxThickness 6e-5;
}

left
{
minThickness 3e-5;
maxThickness 5e-5;
}
}
", which means the mesh has topological changes, the parallization doesn't work any more. (it works fine with single processor).Of2.4.0 is used.

If you could give me some suggestions?

Best regards.

[wangchengan2003]

Dear Jasak,

I try to make parallization for the dynamic mesh problem by using the solver pimpleDyMFoam. The orginal case 'movingCone' works well under parallization process. But if

///////////////////////////////////////////////////
dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solver velocityComponentLaplacian;

velocityComponentLaplacianCoeffs
{
component x;
diffusivity directional ( 1 200 0 );
}
///////////////////////////////////////////////////

in the file 'dynamicMeshDict' is simplely changed as


///////////////////////////////////////////////////
dynamicFvMesh movingConeTopoFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

movingConeTopoFvMeshCoeffs
{
motionVelAmplitude (1.5 0.0 0.0);
motionVelPeriod 0.003;
leftEdge 0.0;
leftObstacleEdge 0.0;
rightObstacleEdge 0.0;

right
{
minThickness 3e-5;
maxThickness 6e-5;
}

left
{
minThickness 3e-5;
maxThickness 5e-5;
}
}
///////////////////////////////////////////////////
, which means the mesh has topological changes, the parallization doesn't work any more. (it works fine with single processor). And Of2.4.0 is used.

I think the problem is similar. If you could give me some suggestions?

Best regards,

[alia]

Originally Posted by hchen

Hi again,,,

For some other cases, I found that the mesh in the processor boundary does not move at all. In the figure below, I impose a rigid body motion on the cylinder and also the mesh near the cylinder. The rest is moving with fvDisplacementLaplacian. However, the point in the boundary does not move at all. Any suggestions and comments are welcome.

This bug has been fixed in foam-extend 4.0

Cheers.

[jiahui_93]

Originally Posted by wangchengan2003

Dear Jasak,

I try to make parallization for the dynamic mesh problem by using the solver pimpleDyMFoam. The orginal case 'movingCone' works well under parallization process. But if

///////////////////////////////////////////////////
dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solver velocityComponentLaplacian;

velocityComponentLaplacianCoeffs
{
component x;
diffusivity directional ( 1 200 0 );
}
///////////////////////////////////////////////////

in the file 'dynamicMeshDict' is simplely changed as


///////////////////////////////////////////////////
dynamicFvMesh movingConeTopoFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

movingConeTopoFvMeshCoeffs
{
motionVelAmplitude (1.5 0.0 0.0);
motionVelPeriod 0.003;
leftEdge 0.0;
leftObstacleEdge 0.0;
rightObstacleEdge 0.0;

right
{
minThickness 3e-5;
maxThickness 6e-5;
}

left
{
minThickness 3e-5;
maxThickness 5e-5;
}
}
///////////////////////////////////////////////////
, which means the mesh has topological changes, the parallization doesn't work any more. (it works fine with single processor). And Of2.4.0 is used.

I think the problem is similar. If you could give me some suggestions?

Best regards,

Hi, i am facing exactly the same problem as yours. Had you found the solution? If yes, would u mind n could you please share with me? Thanks a lot

Sincerely,
Jia Hui