modelling evaporation-condensation in closed system
 

hi
i am modelling a two-phase flow for water liquid and vapor in steady state in a closed system . it contains evaporation and condensation. is using VOF right for this case ? i fill half of the system with water in initialization but after some iteration total mass of system decrease significantly and continuity equation never converge . what's the reason ?
please help me
thanks

I try to simulate the same problem. I use a mixture model with tree phase (air, liquid, vapor). After few iterations I have this message: # Divergence detected in AMG solver. I had try to change the under relaxation value, but is diverge as well.

Hi
You must use a transient solver for a good convergence.
I used a coupled scheme with flow number of 50I used 0.001 s time step to have stable convergence
Good luck

Hi guys,
I'm doing similar problems right now. So did you use Fluent evaporation-condensation model to do the calculation or wrote your own udf for the simulation?

Hi guys,

In my view, if you use VOF to do this simulation, you should write UDF by yourself for the eva-conden process. But if you turn to Mixture model, you can use the written model.