Hi Bernd, I tried running my multidomain model with the AMG-Solver (not yet in parallel). First error that popped up was about AmgTraits not being set. As a first try I used the AmgTraits defined in the el2ppropertydefaults. However, it does not converge. For larger time steps I get warnings from UMFPACK that the matrix is singular. For smaller timesteps the solver does not converge. Maybe I could get the solver to converge if I change some of these traits? I am not sure what these traits should be for a multidomain application (MType, VType, Comm, LinearOperator, ScalarProduct and Smoother). Is there some place I could find information on what to use here?
Kind regards Georg -----Ursprüngliche Nachricht----- Von: Dumux [mailto:[email protected]] Im Auftrag von Bernd Flemisch Gesendet: Mittwoch, 24. Februar 2016 15:32 An: DuMuX User Forum Betreff: Re: [DuMuX] Multidomain in parallel Hi Georg, I think that there is no test case for the multidomain models. You can have a look at test_box1pwithamg and the corresponding problem file 1ptestproblem.hh in test/implicit/1p (or test/porousmediumflow/1p/implicit in the current master) to see how to enable another solver, this time the AMGBackend: #include <dumux/linear/amgbackend.hh> SET_TYPE_PROP(OnePTestBoxProblemWithAMG, LinearSolver, Dumux::AMGBackend<TypeTag> ); I am unsure whether this works in combination with a multidomain setting, please try. Kind regards Bernd On 02/23/2016 03:51 PM, [email protected] wrote: > Hi Christoph, > > We ran our multidomain application in parallel using SuperLU as solver. > However, this lead to an increase in wall time. Since, for now, we do not > solve Stokes flow it might be possible to use an iterative solver for our > fuel cell models and speed up the simulation through parallelization. Is > there a test case using an iterative solver? > > Kind regards > Georg > > -----Ursprüngliche Nachricht----- > Von: Dumux [mailto:[email protected]] Im Auftrag > von Christoph Grüninger > Gesendet: Dienstag, 16. Februar 2016 16:40 > An: [email protected] > Betreff: Re: [DuMuX] Multidomain in parallel > > Hi Georg, > sure, you can use MultiDomain / MultiDomaingrid in parallel. The best > documentation about parallel computing should be the grid howto. You > can download it from the website, see > http://www.dune-project.org/doc/grid-howto/grid-howto.pdf > or build it yourself from the dune-grid-howto module. > > In DuMuX there should be tests that run in parallel, too. But not coupled > ones. > > In DuMuX we introduced the MultiDomain stuff for coupling Stokes with Darcy. > Stokes leads to a saddle-point problem that could not be efficiently solved > by an iterative solver. All direct solvers are not parallel. That's why we > never tried to run the whole problem in parallel. If your assembly is slow, > it still might be worth a try. > > Bye > Christoph > > -- > The method has been developed for use on a high-speed electronic computer and > would be impractical for hand-solution purposes. > [Harlow & Welch 1965] > > _______________________________________________ > Dumux mailing list > [email protected] > https://listserv.uni-stuttgart.de/mailman/listinfo/dumux -- _______________________________________________________________ Bernd Flemisch phone: +49 711 685 69162 IWS, Universität Stuttgart fax: +49 711 685 60430 Pfaffenwaldring 61 email: [email protected] D-70569 Stuttgart url: www.hydrosys.uni-stuttgart.de _______________________________________________________________ _______________________________________________ Dumux mailing list [email protected] https://listserv.uni-stuttgart.de/mailman/listinfo/dumux _______________________________________________ Dumux mailing list [email protected] https://listserv.uni-stuttgart.de/mailman/listinfo/dumux
