The default of 10 coefficient loops per timestep is usually adequate to resolve the strong nonlinearities present in multiphase flows. It may sometimes be necessary to use a larger number during the initial transient. If you feel that convergence is not sufficient with this number of coefficient loops, you should reduce the timestep size rather than increase the number of coefficient loops.

If possible, a transient should be started from a small perturbation of a converged steady-state result. This may reduce the number of coefficient loops required during the initial transient.