Air-water interface in a channel flow using VOF method
 

Hi, everyone.

I'm trying to simulate a two-phase channel flow using VOF model.
There are two inlets (one is for water, the other is for air) and one outlet in the present geometry.
In order to know elevation and shape of the air-water interface and velocity fields, I'll change flow rate or air as a control variable.
The domain is filled with water initially, and air layer will be created beneath the top wall using air injection.

Since both fluids have different inlet velocitis, I think "Open channel flow" option is not applicable. And there is a large vertical distance between the two inlets.
Thus, I made two zones (one is for water, the other is for air).
However, phase selection of Cell Zone Conditions is coupled between the two zones.

Models: Multiphase - VOF
Materials: Fluid
water-liquid
air
Solid
aluminum
Phases: air - Primary Phase
water - Secondary Phase
Cell Zone Conditions: air_interior - (air, fluid) <-- I hope
water_interior - (water, fluid) <-- I hope
Boundary conditions: air_inlet - velocity-inlet
water_inlet - velocity-inlet
air_outlet - pressure-outlet
water_outlet - pressure-outlet

Could you tell me how to separate the phase selection or how to modify geometry configuration?
Otherwise, is there anyone who can provide appropriate examples?

Thank you.
Have a nice day :-)