Nozzle flow

Bharath

Hello, I am modelling a 2 phase ( air and water ) flow through a convergent divergent Nozzle to obtain a fine spray at the exit.

I had indicated atmospheric pressure boundaries at the exit(I created a region after exit...typically an rectangular far field...for visualising the spray ) and found that the solutions werent converging.

If any of you could help me in Modelling this atomization model,I wud greatly appreciate it. I couldnt find a complete source of fluent Modelling procedures for Atomisation models.

Please advice

Thanks

Bharath.