[Deranda]

Hi,

I model a cyclone separator and wann refine the mesh to get y+ values below 5 (or best case <1).
My freestream velocity is about 12 to 13 m/s and I found something like a thumbrule in the steve portal to calculate the near wall distance.

So I changed my primslayer ( oder advanced layer mesher) stretching mode to wall thickness and choose 0.03mm. The prismlayers absolute thickness is 7mm (the meshes base size is 15mm) and the Number of prism layers is 10.
So far so good. The Y+ values during the simulation are 99.8% below 1 and 100% below 5!
BUT there are some SkewnessAngles which have values up to 92 (1% above 85) which could be caused by the small boundary cells.
I tried the polygonal mesher in combination with the prism layer mesher, as well as the advanced layer mesher, but I dont get good y+ values for such a small near wall thickness..

Does anyone has an idea?

best regards
Nils