VOF condensation udf
 

Hi
i use multiphase -VOF model, to model the process of condensation. and I want to add some source terms such as mass and energy. The following is the source :

liquid phase: M=0.1*a1*d1*abs((T1-T0)/T0)
vapor phase:M=-0.1*a1*d1*abs((T1-T0)/T0)

where a1 is the volume fraction of vapor, d1 is the density of vapor,T1 is the temperature of vapor, T0 is the saturation temperature .
how could compile the source terms of UDF. Who could help me? Or give me some hints!

thanks in advanced!