Sinclair Model + secondary turbulence

Yi

hi,

I met a problem when simulating two-phase flows using Sinclair model + secondary turbulence model in FLUENT4.5.6.

1> Turn on (Sinclair model + secondary turbulence). However, the equations to solve do not include particle-phase k & epsilon automatically.

In this case, the simulation gives very good results!

2> Turn on (Sinclair model + secondary turbulence). Also, include particle-phase k & epsilon in the equations to solve.

This time, the (time-dependent) simulation diverges!

3> only turn on Sinclair model (without secondary turbulence)

The simulation results are not good.

Can anybody tell me what is the difference between case-1 and case-2? I tried to seek more details in FLUENT manual, but can't find the answer. I want to clarify the governing equations and auxillary relations employed in the simulation.

Thanks a lot in advance.