Mathematical modeling of porous combustion under various working conditions

Porous burners are known for their high combustion performance, power ranges, and minimal pollutant emissions. This study aims to examine the thermal behavior of premixed CH4/air flames in porous burners utilizing an unsteady in-house computational fluid dynamics (CFD) code. An implicit scheme was employed to solve the transient terms, while upwind methodology was used for displacement terms, and the central difference method solved diffusion terms. The research begins by comparing simulation results against existing published data, followed by investigating how working parameters, such as solid matrix conductivity and volumetric heat transfer coefficient, affect flame structure. Notably, the predicted gas temperature profile close to the reaction zone was observed to be broader compared to that of an adiabatic premixed flame. An increase in the volumetric heat transfer coefficient led to a decrease in local gas temperature in the reaction zone, while solid temperature in the preheat zone increased. Additionally, the study calculated convective heat transfer rates for varying volumetric coefficients and found that enhanced thermal conductivity of the solid decreases downstream solid phase temperature. The findings emphasize the significance of effective thermal conductivity in influencing conductive heat transfer rates within the solid matrix.