Hi Markus, how do you mean to declare the interface as a boundary?
Internal boundaries are treated as "boundary" for imposing boundary conditions, but you don't have double dofs there, isn't it? Best Thomas > Hello Thomas, > > somehow this construction does look really strange for me. I would > declare the interface as a boundary. Then you also have double degrees > of freedom at the interface/"boundary", but you have to use only one FE > on the whole grid. > > Best Regards, > Markus > > > > Am 03.02.11 19:49, schrieb thomas carraro: >> Hi all, >> >> I'm trying to use a hp_collector with two FESystems to solve a >> multiphysics problem. >> >> The idea was discussed during the workshop in Heidelberg in August 2010. >> >> I have two domains (Omega_1 and Omega_2), in both of them I have only >> one variable (u_1 resp. u_2), that has a discontinuity on the >> interface between the two domains, i.e. >> >> in "Omega_1" we have >> >> "u_1 != 0" and "u_2 = 0" >> >> in "Omega_2" we have >> >> "u_1 = 0" and "u_2 != 0" >> >> so I actually need double degrees of freedom at the interface. >> >> The idea was to use a hp_collector like >> >> fe_1 ( FE_Q<dim>(1), 1, FE_Nothing<dim>(), 1 ), >> fe_2 ( FE_Nothing<dim>(), 1, FE_Q<dim>(1), 1 ), >> >> fe_collection.push_back (fe_1); >> fe_collection.push_back (fe_2); >> >> in this way we would have double degrees of freedom only on the >> interface, BUT we have the following problem: >> >> The violated condition was: >> domination != FiniteElementDomination::neither_element_dominates >> >> that makes sense in general, but not in my case, as I will never try >> to restrict my FE_Q to FE_Nothing. >> >> Do you think the idea of a hp_collector is wrong? Any other idea (that >> is not to do everything manually)? >> >> Do you think that it makes sense to skip the function >> "compare_for_face_domination" setting a flag in "distribute_dofs"? >> >> Is it better to implement a special fe_collector for multiphysics >> problem? >> >> >> Any idea is welcome! >> >> >> >> Kind regards >> Thomas >> _______________________________________________ >> dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii >> > _______________________________________________ > dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii > _______________________________________________ dealii mailing list http://poisson.dealii.org/mailman/listinfo/dealii
