Collapsing cells nearby internal geometry vertices
 

Dear All,

I am trying to use snappy to mesh a nozzle geometry.
I am using explicit feature refinement and the domain geometry is well resolved, except at some internal points.

As you can see from the pics below, some cells around vertices (marked in red) are squished/collapsed nearby a geometric vertex.

Looking at the castellated mesh, I noticed that already prior to snapping some flat cells appear in the mesh.

I wanted to ask if any of you experienced the same issue and eventually, how to fix the problem.

I already tried several snappy dictionary tweaks, changing resolution levels, mesh quality thresholds etc., but nothing has helped so far...