Pressure at liquid liquid interface
 

I am modeling the free surface and heat transfer between a droplet and a gas layer. The droplet is at very high temperature and high velocity (eg. in +y direction). The gas released is at low temperature and low velocity in reverse direction (in -y direction). It was expected that the pressure from the gas layer will destroy the shape of the droplet. Anybody know how to include the pressure of the gas at the interface? Kindly give me a clue.

Thank you in advance