Fluent modeling of dense gas dispersion
 

Hi guys,
I'm working on the modeling of LNG gas dispersion.
Before getting to that point, I'm trying to simulate the air flow only in the domain .I'm using a power law for the air inlet velocity((power law: v= 5(z/50)0.55m/s). The boundary conditions are wall for ground, pressure outlet

for air at the end of the domain and I'm not sure about the top boundary condition and the sides. I found in one paper that the boundary condition for top and sides should be air wind velocity tangential to the surface. When I used the same function of air velocity for top and sides I got wrong results of the air profile ( air flow is not the same at the outlet as inlet because fluent introduced the same flow at top and lateral boundary conditions).
Can some one help me to obtain a developed air profile at the end of the domain ?
Thanks :)