Konrad, VectorTools::project_boundary_ > <https://www.dealii.org/8.5.1/doxygen/deal.II/group__constraints.html#ga86427a4e8b3a7e580dabb4e473005288>values_div_conforming > > > <https://www.dealii.org/8.5.1/doxygen/deal.II/group__constraints.html#ga86427a4e8b3a7e580dabb4e473005288>is > > then according to my understanding a pure projection (as the name suggests) > of vector valued functions to the Raviart-Thomas space. This is clearly a > helpful function (for even more than just boundaries) but not in > prescribing flux or traction boundary conditions since, as you mentioned, > this implicitly requires knowledge of the face normal but this is imo not > desired from the user perspective (complicated or changing domains?). For > traction BCs it is even more complicated since that means you need to > prescribe stress tensors. This unfortunately makes it difficult to > prescribe such BCs. > > The strategy that I chose works for the lowest order Raviart-Thomas > element but what about higher order (because the dofs are edge moment?)? > Actually, it should be quite simple to make modify VectorTools::project_boundary_values_div_conforming such that (scalar-valued) flux boundary conditions can be applied. The only places where the boundary function currently enters is in VectorTools::internal::compute_face_projection_div_conforming(https://github.com/dealii/dealii/blob/master/include/deal.II/numerics/vector_tools.templates.h#L6400). In particular, it is only used for multiplying with the normal vector immediately after. You could try to copy the relevant parts out of include/deal.II/numerics/vector_tools.templates.h. We are of course also happy to take contributions in that direction. If you need help with that, don't hesitate to ask.
Best, Daniel -- The deal.II project is located at http://www.dealii.org/ For mailing list/forum options, see https://groups.google.com/d/forum/dealii?hl=en --- You received this message because you are subscribed to the Google Groups "deal.II User Group" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
