Modeling of heterogeneous combustion in porous media under free convection

A mathematical model and a numerical method, based on the combination of explicit and implicit finite difference schemes, have been developed for investigating the unsteady gas flows in porous objects with zones of heterogeneous combustion when gas pressure at object boundaries is known. Used approach enables to solve problems of filtration combustion for both forced filtration and free convection, so it can be efficiently applied for modeling the combustion zones in porous media, which may arise from natural or man-caused disasters. One-dimensional unsteady processes of heterogeneous combustion in porous object under free convection have been investigated using numerical experiment. Two regimes of combustion wave propagation have been revealed – wave movement up and down in the object – and it is shown that these regimes are significantly different in degree of burn of solid combustible material, the temperature in the combustion zone and propagation velocity of combustion wave.