Thank you, Barry and Mark.
The "very fast" cases indeed yield good results, that is, the numerical
solution matches the analytical one. Nevertheless, the usage of PCHypre has
eliminated this strange behavior.
I wasn't aware of the GAMG limitations pointed out by Mark. In fact, for
another
Let me add that generic AMG is not great for systems like this (indefinite,
asymmetric) so yes, check that your good cases are really good.
GAMG uses eigenvalues, which are problematic for indefinite and
asymmetric matrices. I don't know why this is ever working well, but try
'-pc_type hypre'
I would first run with -ksp_monitor_true_residual -ksp_converged_reason to
make sure that those "very fast" cases are actually converging in those runs
also use -ksp_view to see what the GMAG parameters are. Also use the -info
option to have it print details on the solution process.
Hello,
I'm trying to solve Biot's poroelasticity (Cryer's sphere problem) through
a fully coupled scheme. Thus, the solution of a single linear system yields
both displacement and pressure fields,
|K L | | u | = |b_u|.
|Q (A + H) | | p | = |b_p|
The linear system is asymmetric,
