Difference between phi and phiv
 

Hi, everybody.
Usually, for many solvers, in "createFields.H", the face-flux is created by including the header file "createPhi.H". For compressible flows, the header "compressibleCreatePhi.H" is used instead. However, I observed that in the solver "cavitatingFoam", a third header named "createPhiv.H" is used. I cannot understand the difference between "phi" and "phiv". Does anyone has an idea? Thank you very much.

Reviewing both createPhi.H and createPhiv.H the files appear to be identical other than using phiv rather than phi.

Not knowing much about cavitatingFoam but quickly reviewing the solver, it appears phiv is the flux for the vapour fractin. This makes sense as you have a two phase flow you are solving for and each phase will have a different flux.

So the phiv and phi are identical but intended for different phases. I have not done multiphase work and the answer may be obvious if I had, but how does the code distinquish between the phases. Like I said earlier the code is identical. I will take a look at cavitatingFoam to see I can figure it out.