Air flow and combustion simulation
 

Hi,
I am trying to simulate 3d air flow and charcoal combustion in a stove using fluent. It's a non premixed combustion in which the charcoal is placed on a fixed bed (base) of the conical combustion chamber and the and air flow from external source through a closed channel to a perforated cylinder vent at the centre of combustion chamber where it comes out to reacts with the charcoal. How can the charcoal be modelled or inserted and the boundary conditions to be put aside the temperature? posts and tutorials that I have seen are dealing with coal injection at a particular velocity or flowrate with small particle size from an inlet which is not looking relevant in the study. I have set boundary conditions for the air inlet and the outlet, but stuck at the charcoal section. Any help, suggestions or feedback are welcome