yplus
 

hey all

I am modelling air flow with inlet and outlet using standard K-epsilon turbulence model. And got a yplus of 10E8 at a edge of the inlet for steady state simulation. Litrature suggest to be between 30 and 300. What sould I do, to improve it?

thanks

Moh

Re: yplus
 

Yplus should only be available at wall neighbouring cells, so I assume that the inlet intersects with a wall.

In this case the inlet profile would have a big impact on the boundary yplus value since yplus is proportional to wall shear. Try specifying a smooth profile for the velocities at the inlet in order to avoid large wall shear. (I'm guessing that at the moment the velocity is constant across the inlet and then drops to zero at the wall)