roystgnr
commented
10 years ago Would it make sense to add the Lagrange-based pressure restriction that David Knezevic used in one of the libMesh examples? That's probably not as efficient as the PETSc trick but it's completely package-agnostic and it shouldn't interfere with any solver or preconditioner choices.
This would be an alternative to pinning the pressure with a penalty term. We would, of course, still keep the existing penalty version around. Would only apply for using PETSc (which we use most of the time anyway) and only for Krylov solvers, but may be worth it for conditioning at some point and wouldn't be too hard to add.