[bamidoao]

Hello,
I am trying to simulate biomass reaction with sand in a cylindrical fluidising bed reactor. They are both being fluidised by nitrogen so I considered the three of them (sand, biomass and nitrogen) as fluid. However, the biomass sits on the sand before fluidisation by nitrogen. How do I define the region (height) of sand and biomass in the reactor.

Thank you guys and I am waiting for your reply.

N/B: I considered it to be two dimensional.