Hi,
I am solving a transonic Euler flow problem discretized with SUPG. The mesh
is made of Tet4 elements and there are about 7M dofs, which I am trying to
solve over 192 cores.
I had earlier written about the linear solver returning with Inf, and have
since moved beyond that such that I am able to get a solution with the
following command line parameters:
-ksp_gmres_restart 100 -pc_type asm -sub_pc_type ilu -sub_pc_factor_levels 4
-sub_ksp_type preonly
The problem now is that I am limited to very small time-steps (~10e-6),
outside of which the solver starts to choke and the solution diverges. I have
tried other command line options and this above combination is what seems to
provide the best possible solution strategy, albeit constrained in time steps.
I would appreciate any recommendations on solver configurations that may
allow me to take larger time-steps.
Would coding up AMG be a possible alternative (more robust and dependable)?
Please let me know if you need additional information.
Regards,
Manav
