Natural Evaporation Simulation
 

Hello all, I am trying to do simulation of natural evaporation (which occur if Vapor pressure is less than saturation pressure) of water open to atmosphere. My concern is to find out evaporation rate of water with variable humidity of air and I am using species mass transfer model to do the same. But unfortunately I am not getting proper results, I might have done some mistake somewhere. Could you please help me in this regard. Thanks in advance.

Evaporation thin film
 

I am also trying to simulate the same problem but with air flowing above the film.

Have you tried interfaceCompositionPhaseChangeMultiphaseSystem modeling? It is well described at the bubbleColumnEvaporating tutorial.