[rahulrp]

I am Rahul. I am also working on Open Channel Flow in Fluent solver. I used
Mass Flow Inlet bc
mass flow of air is 7985.6 kg/s, free surface of water is at 2m, bottom at 0m,
Pressure Outlet bc

In my case the, the channel is rectangular of cross section 4mx3m. Out of 3m height upto 2m there is water. Now I really dont understand what boundary condition should I use for remaining 1m. The geometry is attached herewith.

One more thing to be discussed is that, should I patched volume fraction of water( secondary phase) initially through out the domain. I am trying for steady state simulation.

Hoping for ur fruitful suggestions.
Thanks.