On Tue, Jun 12, 2012 at 7:56 AM, Thomas Witkowski < thomas.witkowski at tu-dresden.de> wrote:
> There should be no null space from the Cahn-Hilliard equation. You said all those boundary conditions are either Neumann or periodic. I guess it couples to the fluid variables without any null space? > Is there some black-box preconditioner that does not relay on LU > factorization at some point? I know that black-box approaches are mostly > not efficient, but I would have something I can work with. The SVD always works and will tell you about a null space, but of course it's very expensive. -------------- next part -------------- An HTML attachment was scrubbed... URL: <http://lists.mcs.anl.gov/pipermail/petsc-users/attachments/20120612/4511f517/attachment.html>
