How to use UDF in evaporation.
I am working on the refrigerant evaporization in a straight tube which is 860mm long.The diameter is 10mm. The aim is to simulate the vapor volume fraction along the tube.The B.C is: inlet, velocity-inlet, saturated liquid(R134a:a kind of refrigerant); outlet, pressure-outlet; wall, the heat flux is a constant: 10kw/m2. UDF(mass transfer) is needed. But how to define the mass transfer of phase changing from liquid to vapor? Anyone who works on the same topic could give me a help?You will be very appreciated.