Thank you very much Rob. When setting boundary condition on walls, I was not sure which option under the "Film Condition Type" should be used. There are two options: "Boundary Condition" and "Initial Condition". I ran two similar simulations with only difference being the film condition type and the results for film thickness were almost identical.

problem description:

INLET: humid air enters the domain with the velocity of 5m/s, at 27C, and the Species Mass Fraction of H2O being 0.01771.


Walls: thermal condition set as "Temperature" at 15C(to facilitate condensation and film formation) with EWF activated.




For the first case, the film condition type was: Boundary Condition with Film mass flux and mumentum fluxes being zero and Incoming Film Temperature being 27C same as humid air going through the domain.

For the second case, it was set as "Initial condition" with film height as zero and film temperature as 27C.

At the end, contours of "film thickness" looked almost identical for both cases!

My question is that is this expected? what are the differences between two options under Film Condition Type?