y+ values for DES
 

Hi all

As far as I understand the DES uses RANS model at the boundary instead of wall function. However I notice in the results of the turbulence there is a y+ term. Can someone explain ?

thanks
CFT

rans models at boundary works as usual (with and without wall function) it depends on options you choise.

Under "Meshing Requirements for DES," the manual states "The grid resolution requirement in the attached boundary layers is the same as that of a regular RANS solution (10-15 nodes in the boundary layer). In the DES region, the grid has to be designed in all three space dimensions to allow at least the resolution of the largest turbulent structures. As the largest grid spacing is used in the switch for the DES limiter, it is essential to have sufficient resolution in the spanwise direction (if it exists)."

Nothing is mentioned about y+. I would suspect that it shows up in the results for informational purposes or left over from RANS but that it's not critical? I'm not expert though.