Re: [Libmesh-users] BoomerAMG/hypre with CG for elasticity

[John P. <jwp...@gm...>]

On Fri, Jan 31, 2014 at 10:04 AM, Dana Christen
<dan...@ak...>wrote:

> Hello,
>
> I'm trying to solve a linear elasticity problem based on a tetraheadral
> mesh with over a million degrees of freedom.
>
> I've been using the LU solver in MUMPS but I'm now forced to switch to an
> iterative solver because of the memory requirements of that solver.
>
> CG and BoomerAMG in hypre seem to be a good combination, but I've not been
> able to achieve convergence. The residual never goes below 1 even after
> several thousand iterations and shows high oscillations.
>
> The parameters I'm using are
> -ksp_type cg
> -ksp_monitor
> -ksp_converged_reason
> -pc_type hypre
> -pc_hypre_type boomeramg
> -pc_hypre_boomeramg_strong_threshold 0.7
> -log_summary
>

First thing I would think of is that the problem isn't actually symmetric
even though logically it should be?

Does it work any better with -ksp_type bcgs?



> -eps_monitor
> -st_type sinvert
>

Is this an eigenvalue problem too?



-- 
John