I am working in gas-solid two phase flow problem. I wonder which model phoenics use. Is the kinetic theory of granular used by phonics?

Phoenics can solve the two phase flow - gaz -solid in two manners: one using the lagrangian approach through the Gentra module of Phoenics (it is an Eulerian-lagrangian method) the other through a full Eulerian - Eulerian approach using the IPSA algorithm In this approach you can model fluidized bed and many options are available for one to specify a large number of correlations between the gaz and the solid particles

Yes. I am working on the same problem. Using the recompilable abilities of PHOENICS I have incorporated the kinetic theory of granular flow as extra source terms. Also, another approach used is to incorporate more empirical solids pressure correlations as source terms. Kuipers in Holland as published several papers in this regard.