[Usman-Naseer]

Hi everyone,
I am simulating internal flow of an atomizer. I have confusion regarding the exit ''pressure outlet'' boundary condition of my atomizer. As this atomizer is opening into the atmosphere, I should probably assign 101.325 kPa at the exit, but the problem is atomizers work on the principle of pressure jump at the exit of discharge orifice. Due to this pressure jump, a spray pattern is achieved. If I assign atmospheric condition at the exit, there will be no pressure jump. My working fluid is water with air bubbles and i am using VOF model in FLUENT.

I shall be highly grateful for kind reply.