I want to model drying process (momentum, heat and mass transfer) in continuous dryer using fluent.

In this apparatus, inlet port of grain is in upside of hopper, grains exit from bottom-side of it.

Also there are two inlet and outlet ports for entering and exit of hot air separately (in the top and bottom of hopper (.

1-What fluent model must be used?

2- During definition of boundary condition;

What boundary conditions for multiphase modeling must be selected?

Thanks