Sudden non covergence of k-e

Anastasios

Dear friends,

I am running a 3d simulation using k-e turbulence model among others. My simulation is unsteady and converges very well maximum 25 iterations until time step 203. After that all the equations including continuity converge except the epsilon (e)equation from the k-e model.

My flow is a two-phase flow. One primary phase and one secondary granular phase.

Can anyone comment on the sudden non convergence of e?

Thanks very much in advance,

Anastasios