Difference of Wall Heat Transfer Coefficient on different meshes (tetra vs. hexa)
 

Good day everybody.

I had to calculate a Wall Heat Transfer Coefficient (WHTC) on the surface (hub) between red lines.
I did meshing in ANSYS Turbogrid for a 120 degree sector. So I get hexa-mesh with y+=50 at max (right before the fan).

My colleague did mesh for the full circle in ANSYS Meshing with tetras.

We both did calculation in CFX for the same regime (T, Pin, Pout, rotation speed, mass flow etc)
The problem is - we get very differenct results for WHTC - 1 order of magnitude difference. He gets like 25 [Watt/ m2 s], and I get ~250.

We never had any experience with WHTC before.
Does anybody know why this happens?
https://image.ibb.co/bTNOLm/Ris1.jpg