2-phase flow
 

I have been trying to simulate phase change process of water in flow through tube with constant heat flux on tube wall but getting divergence after 10-15 iterations...tried decreasing under relaxation factors & courant number but problem still persists.Tried changing mesh as well but it's of no use.

Model-Eularian RPI Boiling model.
for turbulence-K-epsilon RNG.

Is there anything else that I need to check??
any help on this will be appriciated