Right - maybe I should think about these things before I say them ;-) So now the question is... if you were in my place and wanted to set a u-bc_val type residual for boundary elements... what would you do for tri's and tets? It seems like a post-processing step is the best way (so that something from an element with only a node on the boundary doesn't have a chance to contribute anything). What would that post-processing step be? Are there any facilities already in libMesh that could help out?
I mean, I can certainly loop over the local_active_elements and add all the nodes on the boundaries to a std::vector<Node *> right after I read the mesh... but there is a bit of a problem with adaptivity in this case... and it feels hackish. But I suppose I was hoping that this is what a BoundaryMesh was... so I guess it's not all that much different. Thanks, Derek On Thu, Jun 12, 2008 at 3:25 PM, Benjamin Kirk <[EMAIL PROTECTED]> wrote: >> So how are other people doing boundary conditions with tri's and >> tets? With Dirichlet you can just use a penalty to swamp everything >> out. But with Nuemann? > > Neumann is not an issue because the BC is in terms of the boundary integral, > so you only consider it with elements whose sides intersect the boundary. > The elements who only touch the boundary through a node do not enter into > the Neumann BC. > > ------------------------------------------------------------------------- Check out the new SourceForge.net Marketplace. It's the best place to buy or sell services for just about anything Open Source. http://sourceforge.net/services/buy/index.php _______________________________________________ Libmesh-users mailing list [email protected] https://lists.sourceforge.net/lists/listinfo/libmesh-users
