Thanks for the quick reply,
I am thinking of considering elurian model with granular apporach in which particle diameter will be given as input.
But i am not sure that, two solid phase particle can be interacted through this model(Euler Granular). DDPM is good choice but it will take high computational cost for me.
Also creating injection for static bed is quite difficult, hence i am looking forward to patch the solid domain in simulation.
For your question, yes bed is entrained by the air.
I have use Rocky DEM earlier in my previous corporate experience but i am not sure how to coupled with FLUENT (No Tutorials for one or two way coupling)
Further to the information, after completing the flow simulation, it require to perform phase change and chemical reactions in this problem, for which i am confused to which model will be better suited for me (DDPM or Euler Granular) to go forward.