Boiling Simulation of a Nanofluid
 

Hello everyone.
I want to simulate a boiling flow of a water based nanofluid using Eulerian Boiling model (rpi model) and since the nanoparticles volume fraction is low and the flow is dilute I want to consider the nanofluid as a single phase and run the simulation by changing the properties of the base fluid using udf.
I'm familiar with the basic nanofluids heat transfer modeling (with no boiling) and how to write the define property udf for it.
but in this case, as the boiling happens the water phase volume fraction is getting lower through the pipe and i don't know how to properly change the udf. Can someone help me?

any help would be appreciated. Thanks.