hi can anyone guid me how can i define the interface location in stratifed two phase (air-water) flow knowing that the volume fraction at inlet be given.

Many thanks

You can patch a part of domain with secondary phase vof =1;

you may mark the reqd region using adapt-->region (dont adapt)

Patch the air.vof =1 for the marked region, after initializing

Thanks to the replay. What about the velocity of the secondary phase in the patch region should i give its value in that region. Thanks Saleem

In the case of unsteady simulations you can give the proper intial values through patching. If this is not given, then the value by which you initialize will be taken as initial value.

For steady state, if u know the approximate velocity of patched region, you can provide it, this will make convergence easy.