[jignesh_thaker2007]

How can i define the boundary condition for velocity and pressure at interface of air-water two phase pipe flow in OpenFOAM?
I am trying to solve the problem of two-phase air water mixture in OpenFOAM. Air is coming from the perforated pipe which has number of holes on its periphery and then mix with water. Actually in gambit i gave interface boundary condition at perforated holes. but when i convert in to openFOAM i am finding difficulty to define the proper boundary condition for velocity and pressure at this interface between air and water in 0 directory.
I drew the geometry in Gambit which is attached here for the reference.

Please some tell me what is the proper boundary condition of velocity and pressure at interface for my problem.