Hello,

I'm doing a two-layer simulation of a convective heat transfer problem. But the htran values are calculated very high (about 1000 W/m^2K), although my y+ values are smaller than 1. Hcoef looks fine (about 25W/m^2K). Is htran only calculated for models including wall functions? I have a similar problem with a low-Re-tubulence model.

Thanks in advance, Peter

Hallo Peter!

If you have a look at the definition of HTRAN you see that it uses as reference temperature the fluid temperature in the wall nearest layer. Of course this value is very near to the wall temperature itself when you have very small cells (for example with a mesh for a 2-Layers or a low Re calculation). To compare the STAR results with HTC from the literature you have to use HCOEF and use a suitable TBULK. You can use the OPERATE command to define it properly .

Marco