[rmoreno]

Hi everyone,

I have been trying to run some simulations moving the whole mesh as a rigid body using pimpleDyMFoam as starting point. I can run simple oscillating cases in pimpleDyMFoam and the results agree with the analytical values (i.e. Theodorsen function for an oscillating airfoil).

I want to move now to rhoCentralDyMFoam, as I have been working with it for a while already. If I deform the mesh, I get similar results to what I was getting in pimpleDyMFoam. However, when I try to move the mesh as a rigid body, rhoCentralDyMFoam still asks for a solver, and even if I provide one I think it is mixing the two approaches.

Taking a look at rhoCentralDyMFoam.c I have seen that it calls motionSolver.H and CreateMesh.H, instead of dynamicFvMesh.H and CreateDynamicFvMesh.H. So, it seems that when it was programmed it was not intended to use all the capabilities available in some other solvers.

Can anybody put some light into this?. I have started to modify the code to make it work with solid body motions, but maybe there was a good reason not to do this at the original time and I might just be wasting my time...

Thanks a lot and best regards

[immortality]

hi
Im going to run a mesh with solid body motion.but i don't know how to start in rhoPimpleFoam.could you send me your case?
Another question i didn't get its answer is abot residualControl in rhoPimpleFoam.whats it's duty when we can set tolerances in related dictionaries in fvSolution?

[immortality]

hi
Im going to run a mesh with solid body motion.but i don't know how to start in PimpleDYMFoam.could you send me your case?
Another question i didn't get its answer is abot residualControl in rhoPimpleFoam.whats it's duty when we can set tolerances in related dictionaries in fvSolution?
Thanks.

[rmoreno]

Originally Posted by immortality

hi
Im going to run a mesh with solid body motion.but i don't know how to start in rhoPimpleFoam.could you send me your case?
Another question i didn't get its answer is abot residualControl in rhoPimpleFoam.whats it's duty when we can set tolerances in related dictionaries in fvSolution?

Hi, I do not know about rhoPimpleFoam, I have never used it, only pimpleDymFoam. This is how the constant/dynamicMeshDict file looks

dynamicFvMesh      solidBodyMotionFvMesh;

motionSolverLibs ("libfvMotionSolvers.so");

solidBodyMotionFvMeshCoeffs
{

solidBodyMotionFunction oscillatingRotatingMotion;
oscillatingRotatingMotionCoeffs
{
CofG        (0.25 0.007 0.125);
amplitude    (0 0 0.573);
omega            30.;
}
}

[immortality]

sorry.i corrected it.how can specify which cells are moving and which are stationary ones? Could you send me necessary files?thanks.

[rmoreno]

Originally Posted by immortality

sorry.i corrected it.how can specify which cells are moving and which are stationary ones? Could you send me necessary files?thanks.

The dynamicMeshDict file I shared is all you need to move the mesh rigidly, it all moves as a solid. If you want to specify only certain zones I think you need to use AMI, but I have never done it...

[immortality]

thanks.these show what i want to model.

[immortality]

does anyone could help on how can it be simulated?how to start?

[immortality]

Ruben do you know how can i set in the dictionary you wrote for a linear displacement solid body motion?

[rmoreno]

Originally Posted by immortality

Ruben do you know how can i set in the dictionary you wrote for a linear displacement solid body motion?

It should simply be oscillatingLinearMotion, you can see the dictionary and any other available solidbody functions in

src/dynamicFvMesh/solidBodyMotionFvMesh/solidBodyMotionFunctions/*

[immortality]

thanks.but i dont want oscillating motion.how to set linear constant velocity motion?

[yardsail]

Hello,

I just tried the same thing, starting with the tutorial oscillatingInletACMI2D and modifying it to use rhoCentralDyMFoam instead of pimpleDyMFoam.

Just like the OP, it asks for a solver even though it shouldn't use one for the prescribed solid body motion.

Here is my dynamicMeshDict file:

FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant";
object dynamicMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dynamicFvMesh solidBodyMotionFvMesh;

motionSolverLibs ( "libfvMotionSolvers.so" );

solidBodyMotionFvMeshCoeffs
{
cellZone inletChannel;

solidBodyMotionFunction oscillatingLinearMotion;

oscillatingLinearMotionCoeffs
{
amplitude (0 0.5 0);
omega 3.14; // rad/s (.5 rps)
}
}

This is an old thread, but I wonder if anyone has found a workaround?

Thanks!

[CHAYANIT]

For mesh movement my dynamicMeshDict file is as follow


dynamicFvMesh solidBodyMotionFvMesh;

motionSolverLibs ("libfvMotionSolvers.so");

solidBodyMotionFvMeshCoeffs
{

solidBodyMotionFunction oscillatingLinearMotion;
oscillatingLinearMotionCoeffs
{
amplitude (0 0 0.573);
omega 30;
}
}




It is working fine on airfoil pitching. But can anyone tell me what is meant by amplitude and omega in this file.What amplitude and omega is it referring to and is this fine to work on pitching foil?
Any reply would be appreciated.
regards
Chayanit