hi all

when i make grids in my airplane in order to compute results at Ma=0.2, alpha=8, i use SST model, auto wallfuntion , i posted a computed result and see Y+=30-300,

but the help files say if low Re model(such as SST),Y+=2.0 , in boudarylayers, there must be 10 points, or SST model can also accept wall Function, so i want to know how i set Y+ in SST? would you tell me the true way if you have some idea?

Hi Zuozicheng,

as I understand the manual, the SST model automatically adapts itself whether or not it is using wallfunctions depending on the local Y+, i.e. the grid resolution. So, if you think a small Y+ is beneficial for your simulation, create a grid with a fine boundary layer resolution and CFX will use the SST model without wallfunctions. Otherwise, if the grid is coarser in the boundary layer, wall functions will be applied.

Hth,

-Thomas

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