Thanks a lot, Daniel and Wolfgang! What I understood was that since the SUPG and PSPG terms are integrated over the cell interiors so the laplacians can be ignored while using Q1/Q1 element without any singularity problems on the cell edges.
Thanks! Feimi On Wednesday, January 17, 2018 at 2:36:39 PM UTC-5, Wolfgang Bangerth wrote: > > On 01/17/2018 11:59 AM, Daniel Arndt wrote: > > These terms are simply zero if you consider Q1 elements for the > velocity. I > > That's true only if you're on affine meshes. In general, the Laplacian > of a Q1 function on an arbitrary mesh is not zero. > > That doesn't mean, though, that it may not be valid to just ignore the > issue. > > But I think what you want to say is that the term is supposed to be > interpreted as a sum over cell interiors, not as an integral over the > entire domain. In the latter case, you'd have to worry about the fact > that Delta uh is singular on edges, whereas in the former you ignore > these contributions. > > Best > W. > > -- > ------------------------------------------------------------------------ > Wolfgang Bangerth email: [email protected] > <javascript:> > www: http://www.math.colostate.edu/~bangerth/ > -- 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.
