How to let only one phase exit the pressure outlet in Eulerian-Eulerian model
 

Dear all,

I am using Eulerian-Eulerian model in Fluent to simulate a sieve tray with a gas velocity inlet, a liquid velocity inlet, a gas pressure outlet and a liquid pressure outlet, now I am confused with how to realize that at the liquid outlet, only liquid was assumed to leave the flow geometry and only gas was assumed to exit through the vapour outlet?
I guess that a udf may be necessary for the gas and liquid outlet, because to my knowledge, Fluent itsself can not fullfill our boundary condition in Eulerian-Eulerian multiphase simulation.
Probably I went wrong somewhere. If anyone have anyone idea, please kindly help me.

Thanks in advance.

Shen