Setting boundary conditions for front injection
 

Hi everyone.
I would like to replicate the conditions that we could find in a wind tunnel, in particular the one involving the front injection useful to manage correctly the boundary layer on the ground. I have already divided the lowerwall in two "walls" so that I can easily apply two different boundary conditions (before the injection and after the injection). Do you have any idea about the best setting? I thought to apply slip in the first part and then the wall functions but i am not sure that we are exactly modelling the case.