[petsc-users] KSP diverging

[Jed Brown]

On Thu, Dec 22, 2011 at 19:20, Mohamad M. Nasr-Azadani <mmnasr at gmail.com>wrote:

> Any hints on what is happening here or how I could narrow it down?


I would start by following the general advice in the FAQ

http://www.mcs.anl.gov/petsc/documentation/faq.html#kspdiverged


> I know that we had an early discussion on the convergnce for the
> incompressible CFD problems and boomerAMG preconditioning,


That was about solving the coupled system. That shouldn't be an issue for
the Poisson problem.


> but it seems that for this case, that is the only one that does not blow
> up for most of the time integration I have.


Since this problem only occurs after long time integration, you might
consider writing out the model state when you see divergence so that you
can experiment with alternative methods quickly.
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