Numerical simulation of combustion and ignition-quenching behavior of a carbon packed bed

A two-dimensional axisymmetrical numerical model for combustion of a carbon packed bed is presented. The model is set up by coupling a gas-particle two-phase flow inside the bed to a stagnation point flow in the boundary layer on the bed surface. The PISO algorithm is employed for the solution. Computations have been performed for the two limiting cases of a Frozen and of an equilibrium flow as well as for finite homogeneous reactions rates. The combustion rates of the packing for various parameters and the parameter distribution profiles are obtained. The ignition and quenching behaviour of the packing is also investigated and discussed. The model is useful for the simulation of the smoldering combustion and its transition into flaming.