How to model granular flow through porous media
1. How to model porous media region?
Previously I thought drawing several big spheres in a cube in Gambit or Ansys Workbench to represent the porous media region, then mesh, then import to fluent. Then I realized maybe I should just draw a cube, and define it as porous media in fluent. Which is the right way? and The question is how to do it in fluent? I want to define the porousity and the size of spherical particles which compose the porous media. 2. How to model the interaction between porous media (big spherical particles) and the granular flow? the granular flow contains small particles and water, and by defining the interaction between this small particles and the porous media (big spherical particles), the deposition or transport behavior of small particle in the granular flow could be modeled. 3. If the above steps can be accomplished, then is it possible to see the process animation of the granular flow including small particles transport through porous media, and some of them attach to the porous media (big particles)? Thanks for any suggestions and comments. 
are you read manual??
I think for these modeling you should use porous & discrete phase models together or use multiphase modeling that explanations of all them are very well in manual.hope it be useful.

There are different models
You can do it both ways, it only depends on the model you´re trying to simulate

All times are GMT 4. The time now is 15:56. 