convergence difficulty
 

Hello Everyone, I am trying to run the heat transfer between licl solution and air in duct. The flow is counter flow and the solution is modelled as falling film. The surface tension is applied between liquid and air. Both air and licl solution are modelled as species and VOF is considered as multiphase flow. I did the coupled pressure velocity coupling and pseudo transient. The time step is user defined and 0.001s. But the solution is not converged and even I am not getting the mass balance. Thank you in advance for your suggestion.