Divergence after change in mass flow rate in two phase flow
 

Hii...
I am doing simulation of two phase turbulent flow through the pipe. Primary phase is liquid and secondary phase in gas. When problem is initiated calculations are going in proper manner. After few time steps flow get steady.
But when i increase mass flow rate after flow get steady, the problem of turbulent viscosity limited to viscosity ratio of 1.000000e+05 in cells occurs and after few time steps divergence occurs.

How to avoid this problem? How to keep calculations going in proper way.

What is/are your outlet condition(s)?