Modeling of unsteady filtration gas combustion

Unsteady filtration gas combustion with various gas flow parameters is studied by mathematical modeling. Transition processes due to a sudden change in the calorific value of the gas mixture, gas flow velocity, and flow direction are considered. Trends and mechanisms of change in the structure of the filtration gas combustion wave and its propagation velocity are analyzed for various types of transition processes. It is found that with a sudden change in gas flow parameters, the flame can abruptly move large distances in the porous medium. Subsequently, at the new flame localization, a wave of filtration gas combustion forms which corresponds to the changed parameters of the gas flow. If in the porous medium, the amount of heat is insufficient, the transition process ends with quenching. As the gas flow direction changes, the combustion wave continues to propagate in the former direction for some time, which can lead to the spread of the high-temperature zone in devices based on the reverse process with a homogeneous gas-phase reaction.