On 07/26/2013 01:08 PM, Ankit Mahato wrote:
Hi R,
Spectral/hp element method will require a strong mathematical knowledge to proceed. Chlorin Projection method is widely prevalent but it requires a separate
I had a talk with a professor who suggested me the following: formulation of matrices and not our current formulation.
What do you mean by separate formulation of matrices? Having the individual matrix blocks? That is certainly possible. You would have to write a special solver making use of that, yes.
GMRES with ILU(0) preconditioning may still not work for convection dominated problem(our main PITA) and he told me that there are schemes to handle convection dominated problems where some some terms are added which die with successive iteration and I should look for these schemes on the internet.
We do have stabilization terms, see [1]. The problem is they depend on some parameters and I never worked enough with those terms to learn how to use them properly. It is easy to over-stabilize. And you still have to solve the linear system. As you said that the Reynolds numbers would not be high in your problems, I would try GMRES with ILU(0) anyway.
r.
[1] http://docs.sfepy.org/doc-devel/examples/navier_stokes/stabilized_navier_sto...
Regards.
On Thursday, 11 July 2013 19:27:23 UTC+5:30, Robert Cimrman wrote:
On 07/10/2013 09:16 PM, Ankit Mahato wrote:
On Wednesday, 10 July 2013 18:06:26 UTC+5:30, Robert Cimrman wrote:
On 07/10/2013 01:53 AM, osman buyukisik wrote:
On 07/09/2013 12:29 PM, Ankit Mahato wrote:
I went through the codes I mentioned above: The following solvers were good but were licensed under GPL DUNS 2d/3d navier Stokes - GNU GPL license 2.0 Channelflow - GNU GPL2 OpenFlower - GPLv2 PETSc-FEM - GPLv2 Tochnog - GPL
Ankit, I think Fenics project's application cbcpdesys might be the best
is in python and solvers are mainly called from python. Has a few turbulence models already coded. Might be a good idea to look how they did it (it is FE based). None of the codes you listed is python based. Another FE based solver that may be scripted with python is Fluidity from http://amcg.ese.ic.ac.uk/index.php?title=Fluidity again just to investigate how they do it.
You might want to think about using petsc solver suite (from Argonne National Labs) to be called from python as in fenics/dolfin. It has quite a few choices for solving nolinear systems. Its license seems very liberal (like bsd).
You'll need to solve not NS but Reynolds averaged NS. This ends up
adding additional equations related to turbulence. Just NS by itself will
as it diverge as
the Reynolds number goes above a certain value. All of this already done in cbcpdesys. It is GNU LGPL so should be ok to use with bsd. But you won't be copying verbatim anyways.
just a few thoughts. I use fluent at work and many open cfd codes at home. Regards, Osman
Thanks for the links! fenics is always a good source for inspiration.
BTW. Ankit, what Reynolds numbers are typical for the flows you would
choice like
to simulate?
Haven't calculated yet for the final problem. but would go with low reynolds number for pipe flow and the phase change part itself has low reynolds number in the cavity.
Good. That means less worries about the convective stabilisation.
r.