Why condensation is not happening for my system?

hassan14069 Member Posts: 1

So I have been working with the evaporation-condensation model in fluent for quite some time, but I haven't been successful in acquiring the condensation capacity I was expecting. I have been trying to perform condensation of water vapor to water liquid in a single pipe just as a demo using 2-D system. The pipe had a diameter of 12mm and a length of 500mm. I've kept velocity inlet boundary condition with a velocity of 0.13m/s and temperature of 120 degrees Celsius. I've kept the pressure outlet as my outlet boundary condition and I've kept the wall temperature at 35 degrees Celsius. I've used VOF model Tsat = 100 Degrees Celsius and from to frequency as 0.1 and 180 (I've acquired this from other forums and even tried increasing the value to more than a1000). I've tried several ways and changed different parameters, but I still couldn't get the condensation to occur even though the solution converges, and the temperature goes below the Tsat. I even tried to model using udf source term for condensation modelling. What is the problem and how can I get condensation? Thank you in advance.