Unrealistic results in Rising Steam Condensation

[nitinminocha]

Dear NimaSam
I am facing some problem in simulating rising steam condensation on cold walls. Rising steam is taking liquid film alongwith it. Please have a look and give your suggestions.

My Boundary conditions are:

and the results are:

Thank You
Nitin Minocha

[NimaSam]

Dear Nitin
your BC is not valid, because you considered a fixed inlet Velocity and also you forced the outlet has no back flow, so it is reasonable that liquid film moves up!
maybe, it is better to divide the inlet into two sections in the main section, you can apply the fixed inlet velocity but near the cold wall consider zeroGradient or pressureInletOutletVelocity

Best regard