Good Morning, After many steps I'm not able to solve my coupled matrix with iterative solver. The matrix is defined as the discretization of the Navier Stokes equation in a pressure based form. Also for a small case of 70K cells the linear solver blows up (GMRES(ILU BJACOBI) , BCGS(ILU BJACOBI)) and HYPRE+BOOMERAMG). For the boomerAMG I use this options: -ksp_monitor_true_residual -pc_type hypre -pc_hypre_type boomeramg -pc_hypre_boomeramg_max_iter 5 -pc_hypre_boomeramg_cycle_type V -pc_hypre_boomeramg_relax_type_all SOR/Jacobi -pc_hypre_boomeramg_grid_sweeps_down 3 -pc_hypre_boomeramg_grid_sweeps_up 0 -pc_hypre_boomeramg_grid_sweeps_coarse 3 -pc_hypre_boomeramg_rtol 0.0001 -pc_hypre_boomeramg_coarsen_type modifiedRuge-Stueben -pc_hypre_boomeramg_relax_type_coarse SOR/Jacobi -pc_hypre_boomeramg_interp_type multipass-wts -ksp_max_it 60 -ksp_type richardson -ksp_view but without any success. That's really frustrating because of direct solvers are able to solve the matrix without any problem.
Do you have any suggestion of why can I have all this issues? Your help and support could be really appreciated. Thanks in advance Luca -- Hochschule Luzern Technik& Architektur Technikumstrasse 21, CH-6048 Horw T +41 41 349 33 11, F +41 41 349 39 60 Maschinentechnik CC Fluidmechanik und Hydromaschinen Dr. Luca Mangani - PhD Senior Research Fellow T direkt +41 (0) 413493 248 luca.mangani at hslu.ch www.hslu.ch/fmhm
