Preprocessing unstructured grids (tetrahedral mesh)
 

Hi,

I have recently started writing a 3D finite volume code. I am currently stuck in preprocessing the grids.

I would like to know the algorithm to construct the face neighbours (i.e. left cell and right cell to a face).

rakshith

hi

Do you mean you have the grid in a certain format from an external software and you want to do the calculation with your own solver? I recommend you to use Gambit, Icem, etc for meshing and export the mesh in .msh format. This file contains the information about the left and right cell of a face.

Thanks a lot for the info. But I do not have access to any of the licensed grid generators. Hence I am using free softwares. Therefore I need to do all the preprocessing before it is fed into my solver.

Which software are you using?

For Gmsh, you probably need to match the nodes number to find the neighbours. And depending on your selected surface orientation, you will find the left and right.

If you are using open-source software, you may want to find another open-source software that reads the specific mesh format to see how they go about it.

Good luck
Julien