Hi, Previtali

Thanks for you concern! But I want to know if first layer grid with y plus between 1 and 30 is work with insensitive wall treatment, since user guide said:

When wall functions are used, it is essential to avoid meshes with values lower than ~30 as the wall shear stress and the wall heat transfer can and will seriously deteriorate under such conditions. For this reason, the usage of y+-insensitive wall treatments is recommended.

So it recommended the  y+-insensitive wall treatments for the corase mesh when wall function is used, but it did not mention if y+-insensitive wall treatments will also “Deteriorate” the boundary layer result when y+ <30 ?

Thanks again!