Dear Tims, Do you monitoring the convergence? Try it a see if you have stagnation in your convergence. However you can try this setting, -ksp_type gmres -ksp_gmres_restart 30 -pc_type asm -pc_asm_overlap 2 -sub_pc_type ilu -sub_pc_factor_zeropivot 0 -sub_pc_ilu_levels 3 Regards,
> Dear all, > > the more KSP and PC methods are available, the more difficult it is to > choose a suitable one. > > I want to compute Navier-Stokes (using Finite Elements) for > medium-sized Reynolds numbers (still laminar, though). I am currently > using > > -ksp_type gmres > -ksp_gmres_restart 30 > -pc_type bjacobi > -sub_pc_type asm > -sub_pc_asm_overlap 2 > -sub_sub_pc_type ilu > -sub_sub_pc_factor_zeropivot 0 > -sub_sub_pc_ilu_levels 1 > > but with a large number of CPUs (e.g. 20), no convergence is achieved. > Does anyone have some suggestions for a better setting? > > I am using petsc-2.3.0. > > Best Regards, > > Tim > > -- > Dr. Tim Kroeger Phone +49-421-218-7710 > tim at mevis.de, tim at cevis.uni-bremen.de Fax +49-421-218-4236 > > MeVis Research GmbH, Universitaetsallee 29, D-28359 Bremen, Germany > > Amtsgericht Bremen HRB 16222 > Geschaeftsfuehrer: Prof. Dr. H.-O. Peitgen > >
