gas-liquid-liquid multiphase problem
 

hi,guys!
i am studying a gas-liquid-liquid problem. liquid1 is below.liquid2 is above.the interface between liquid1 and liquid2 is free surface.there is a lighter gas source among liqui2.the drag between liquid2 and gas is negligible.the drad between gas and liquid2 is not negligible. how can i deal with this kind of gas-liquid-liquid problem.
thank you.