CFD Online Discussion Forums - cas file to msh file

I may be wrong but this is what I belive: The multigrid methods are based on coarsening of meshes and solving pdes on the coarse grids thus generated, then transfer of the solution to fine meshed, known as restriction and prolongation. The reason is when we use solvers as Gauss Seidel, as the mesh sizes decreases the difficulty in convergence increases, error behaves something like proportional to 1/h , where h is grid size. So the basic idea of multigrid method is to solve for large h and transfer the solution to finer meshes. On structured grids this can be obtained by simply not considering alternate node, and on unstructured meshes , the data structure that stores the mesh is Graph, so this can be obtained by simply collapsing some edges in some direction. So considering this, the multi grids are generated at the data structured level and the memory occupied by them is released as soon as the solver run finishes. This all suggests that the multigrids are not stored in case files (since dynamic allocation takes place and allocation can vary with multigrid parameters). So in my opinion we can not get the multigrid meshes so generated in case file.