asymmetric 2d diffuser boundary condition
 

hello i'm trying to solve a 2d asymmetric diffuser in ansys 12. Steady flow, constant density, pressure based, turbulent k-e model.

Some questions:

1 - as boundary condition i've chosen velocity inlet and outflow.

i didn't choose pressure outlet because i think that if i fix the pressure i will obtain an unrealistic solution because in this way the system is forced to reach the pressure that i established. it is a good consideration?


2 - i have to use the standard wall function and then enhanced wall function. in the first case y+ must be around 30 so what you advice about mesh?


thanks

hello new problem: i'm trying to solve the problem with k-e enhanced wall. A strange thing happened: i've done 3 meshes (350x200, 350x250, 350x300) and i'm trying to obtain mesh independence results. The 3 mesh above give similar result but when i solve a finer mesh 350x350 the solution completely change!!! how it is possible?

help please