Hi everybody, I am currently implementing a semi-Lagrangian advection solver in deal.II.
Everything works fine in periodic domains, but now I want to define boundary conditions that depend on the gradient of the solution at the boundary. When I use Lagrangian FE_Q elements, the gradients are discontinuous at cell interfaces, giving me a gradient that is non-unique at edges/vertices. Is there a way to obtain a unique gradient? Of course, I could work around this by taking the average gradient over all cells that contain the DoF, but (a) this seems like fudging and (b) I would need to iterate over all neighbors (and neighbors of neighbors) to calculate the gradients at a edge or vertex. Does anybody know a neater solution? I noticed that cubic splines are implemented in 1D, but going to 2D seems cumbersome - and I would be probably running into (b), again. Thanks in advance. Best, Andreas -- 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 dealii+unsubscr...@googlegroups.com. For more options, visit https://groups.google.com/d/optout.
