Dear all, I am working on multiphase flow (specifically gas-solids flow in pipes) simulation using fluent4.5. But here I still have some doubts on it.

First of all, when we using the dispersed turbulence model, it says that the collisions between particles are neglected. Does it mean that fluent does not solve the granular temeprature equation? And how does that affect the momentum equations

And if we use secondary turbulence model, we need to provide the turbulence k-eps model for solid phase. How does that affect the granular temperature equation and momentum equation?

Has anyone ever worked on the similar problem? I would appreciate if you can share your experience with me and give me some advice on it.

with BEST RGDS,

daninwin

Dear Daninwin

I believe "collisions between particles are neglected" means that the FLUENT model do not take into account the collision between particles. This assumption is fine if you have a dilute particle system, where the effects of particle-particle collision is negligible.

The latest versions of most commercial CFD package can deal with particle->fluid and fluid->particle interaction, but as far as I know, none of them can deal with particle-particle without additional inputs from the user.

With respect to the momentum equation, you need to be concern about the momentum transfer between the solid and fluid phase, especially if you have a dense particle system. I am not too clear how FLUENT 4.5 handles this or what the above mention "dispersed turbulence model" involves.

Hope this is useful. Perhaps someone else can give a better explanations or correct me if I am wrong.

Lily Kabanj