Guilin Sun
Ansys Employee

in finite element method, when an anlge is too small, the triangle mesh quality is poor. High quality triangle means the angle range inside the triangle.  High quality triangle means the the mesh is well defined.low quality means there might be some triagles with small angles.

Usually we do not suggst to use constraint mesh for the whole simulation area. You can use smaller edge length and more iteration number to get finer mesh.