[breznak]

Hello,

I am trying to simulate a pipe internal flow and surface roughness is up to Ks = 1.25e-3 m.

For transition sst model it is recommend that the y+ should be smaller than five in whole cfd domain.

But, to deal with such high roughness, y-value from wall to the first cell point, y_p, should bigger than Ks. And for my boundary condition y_p should be almost 1e-5 m for maximum y+ < 5.

In this case, I should use only like k-ep model to adapt for example standard wall functions so I can make a mesh with y_p bigger than Ks?