Problem in cyclone simulation

JiChun

Hello, everyone,

Right now I am solving a cyclone problem and getting some troubles.

1) It is very difficult to get converged results. Even if I get a converged result, I still doubt if it is correct because the result shows that there is no reverse flow occuring at one of the outlets.

2) According to the Fluent manual, I should use RSM turbulent model to simulate this case(for strong swirling flow), but this model fails to give me a converged result. While RNG and realized model give me a converged result.

3) Some funny things happened. Sometimes I got a converged result with reverse flow at one of the outlets and sometimes not.(I used the same boundary conditions)

Bye the way, my current computational grids are tetrhedral elements( It is hard to use hex elements to generate the meshes for this case). Could this a problem?

Your advices and suggestions are highly appreciated.