Mesh Quality at the Interface

Can Atli

Hello All,

My question is about the meshing with tetragonal elements. Why do the tetragonal elements yield poor mesh qualities, even if you are meshing a very simple geometry like a cube?

I have a complex 3d geometry, which i divided into 3 volumes. The two volumes were meshed with hex elements, no problems, perfect quality. But, the remaining volume (the one with narrowings, fillets, etc) had to be meshed with tetragonal elements having poor quality. The quality is even worse at the interface between hex&tet elements even if the element sizes match.

I tried to perform a segregated, steady state flow analysis, but could not achieve convergence, possibly because of this mesh problem.

What do you suggest? Thank you for your assistance,

Can

Hi Julie,

sounds ok. A skewness of 0.94 is not yet a disaster. The grid resolution should be ok to give an idea if the flow, if there are no recirculation regions or so. What about your Reynolds number? Have you looked at your Y+ values?

Why unsteady state? Is your flow unsteady? If you are lookinf for a steady state solution, you should use the steady solver. If your flow is unsteady, then how did you initialise your solution?

So you used a Tet-mesh all over? Can't you split the volume into smaller parts an mesh most of the geometry using a hex-mesh?

kind regards, Laika, still orbiting