Two phase flow, water not come out through the outlet
 

Hello

I am trying to solve two-phase air + water flow in a straight pipe.
There are two inlets in the left side of the pipe. An air inlet and a water inlet.. There is one outlet only, for both air and water on the right side of the pipe.

The inlet air velocity is higher then inlet water velocity

When running the simulation, it seems that the water does not come out through the outlet. It looks like the water is treating the outlet like a wall.

The air does come out through the outlet

I am using Open foam Version v1912 and a solver compressedInterFoam

Guess the problem is with the Outlet boundary conditions of alpha.water and U.

The boundary conditions for outlet are:

For Alpfa.water
outlet
{
type inletOutlet;
inletValue uniform 0;
value uniform 0;
}

For U
outlet
{
type zeroGradient;
}

So how to make the water come out through the outlet.

Thanks for help.