open channel flow model VOF in fluent
 

Dear All,
I need your help,
1- I am using open channel flow model VOF in fluent figure attached below ,
2- Boundary condition I apply pressure inlet and pressure out let with velocity magnitude 0.3 m/sec.
but problem is solution did not converge or if converge the lift and drag force is high figure attached.

3- Solution scheme is used simple one

please, please if you have any related tutorial send me ( yasar248@gmail.com)