Dear Wolfgang, dear Bruno, Thank you very much again for your time & effort!
I think one should leave grad-div stabilization out of the discussion, since it is only used as a counter-measure. It has nothing to do with inf-sup stability, but is rather used to additionally penalize violations of continuity of mass in the case of stabilized formulations through a penalty-term in the balance of linear momentum. I also checked up on the literature in V. John s book from 2016: FEM for incompr flow problems and what I found is, that in example 4.100 for stabilized Stokes shows nicely, that the velocity is converging quadratically & the order of the pressure convergence depends on viscosity and is in [1,2] for q1q1 elements (nu = 1e-10 giving ~2). So summing up, I was simply expecting too much it seems! Best wishes & kind regards from Austria, Richard -- 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. To view this discussion on the web visit https://groups.google.com/d/msgid/dealii/5022df17-a2b3-42bf-8abd-4ee43ac0f80a%40googlegroups.com.
