How to write UDF to achieve phase chang
 

I want to write UDF that can achieve the phase change such as boiling, but I must use the Eularien mutiphase model and tubulent. I try to add the UDF than is successful in VOF, miture and Eluraien laminar model to the fluent, but it doesn't work on Eularien tubulent model.

So, who can help me find a UDF that can achieve in Eularien tubulent model?