[eman]

Hi guys,
I'm new in this forum and I'm very grateful if someone can help me. I’m trying to setting my model of bubbling fluidized bed reactor with Ansys Fluent, but I found some difficulties about implementing drag law for discrete particles. I would simulate a bubbling fluidized bed reactor (2 eulerian phase: i.e. air and sand) with injection of solid particles to simulate biomass particles.
I used Eulerian multiphase model with 2 Eulerian phases (bed material and fluidizing agent: air), to simulate the bubbling fluidised system. To introduce a particle (simulating biomass) in the bed, in the multiphase model, I considered the Dense Discrete Phase Model with one Discrete Phase. Now I can set discrete phase properties (set as granular) and injection properties selecting the Drag Law form the Physical Models tab (syamlal-obrien). Now in Phase Interaction dialog box, I can set the model for interaction between fluid phase. I set gidaspow model for primary (air) and secondary (sand) eulerian phases interaction, but I get only ‘averaged-discrete-phase-drag’ as drag coefficient among Eulerian phases and the discrete one. This corresponds to the Kdpm factor used in the momentum conservation equation for the discrete phase (it is essentially the drag coefficient). During simulations, I noticed that no interaction exist between eulerian phases (air and sand) and the solid particle injected. This latter falls down as no interaction exist with the air and the sand. It is only reflected by reactor walls. Where is the mistake?

Thanks in advance for your time.

[newton2009]

why you consider discrete phase model?