Hey there,
I’m working on a fluid flow and due to the requirement of periodic bc, I switched to gmsh for mesh construction where something happened, I can’t explain. When switching from mshr mesh to a gmsh mesh, the qualitative behavior of the PDE changes. So, I started to doubt the mesh construction and everything else and ran a few simple tests. One of it was to import the mesh, invoke a empty function and apply a DirichletBC to the area of interest. This is the result for the mshr mesh. It is as I wish and everything is fine:
However, when doing the exact same thing to the gmsh mesh, this is the result:
These white spots are distorting the simulation, because the red spots correspond to a no slip condition in my fluid simulation. Due to the white spots the simulation becomes nonphysical. What is happening here?
Kind regards
Max