[Trinxo123]

Hello,

I am carrying out FSI simulations using preCICE, I am simulating an axial fan by using a moving reference frame approach. In order to couple the structural solver with the fluid one, a dynamicMesh has to be set so that the displacements calculated by the structural solver are applied to the CFD mesh, the problem with this is that dynamicMesh applies displacement and velocity to the faces of the impeller, resulting in the velocity of the impeller being 0 instead of rotating as with Moving Reference Frame alone. The displacements are tiny, so I only care about the rotating velocity and not the deformation velocity of the impeller.

The current options for the dynamicMeshDict are:

dynamicFvMesh dynamicMotionSolverFvMesh;

motionSolverLibs ("libfvMotionSolvers.so");

solver      displacementLaplacian;
// OpenFOAM9 or newer: rename "solver" to "motionSolver"

displacementLaplacianCoeffs {
    diffusivity quadratic inverseDistance (externalwall-rotorcfd-tht100-rotorcfd-tht100 externalwall-rotorcfd-tht100-rotorcfd-tht100_1 externalwall-rotorcfd-tht100-rotorcfd-tht100_2);
}

I do not know if there is some option to indicate that the velocity field should not be updated or handled, or maybe a better dynamicMesh option would be suitable. Unfortunately, I have tried to modify the dynamicFvMesh library by erasing some lines that were changing the velocity, but It hasn't worked. The other thing would be to prioritise the MRF dictionary over the dynamicMeshDict, don't know if that's an option.

If anyone has some suggestions I would appreciate it! Thanks,

Marc