SimScale CAE Forum

Problem importing UNV mesh for MRF analysis

I am unable to set up a MRF analysis, starting with a mesh created in Salome, imported to simscale as a UNV file.
In Salome the mesh is partitioned, with the two volumes and all faces in mesh groups. After importing and setting up the problem, I get the error:
Error: Please choose valid cell zone(s) for the following Rotating Zone:
Rotating Zone 1

The public version is:

Are there directions for importing unv meshes for this type of analysis? It looks like somehow there needs to be cell zones set. In standard openfoam this would be done by converting the unv file to foam, then setting the cellzones.

Hi @aminer2k!

To me it is not very clear what you want to achieve with the amount of boxes you have covered the polygon with. Couldn’t you just put the polygon in the middle of a big cylinder and use the MRF approach then? Maybe the @PowerUsers_CFD can grasp your concept and give you some tips on that one. An example that might help you out can be found here: MRF .



Thank you for looking at this problem.

I am not sure what you refer to when you say “the amount of boxes you have covered the polygon with”. Perhaps you refer to the mesh?

This is a mesh, imported as a unv file. A rather course mesh, made to test how simscale deals with imported UNV files and salome.

The model is a simple octagon in a cylindrical fluid body. The volume is partitioned in salome to create a central moving frame, and an outer stationary frame. This should be a pretty simple test case. Bottom surface is a symmetry plane. Meshed in Salome, imported to simscale. Once in simscale, it is not clear to me how to create cellzones and designate the MRF. Any way I try it, I get the same error, as noted above.

If there is an example of importing a unv and setting up a MRF problem, please let me know. I have not been able to find one. There are examples of importing geometry and meshing in simscale, then doing MRF, but this is not the functionality that I am testing.

Hi @aminer2k!

I am not very familiar with UNV and the functionalities coupled with this format. I will tag the @PowerUsers_CFD here, maybe they can help you out. What I would have done in this case is to put the polygon in a simple cylinder and use the cylinder with MRF as you maybe have seen in the documentation. Let me try it with your geometry later on and I will get back to you as soon as possible.