Abstract
The present study considers the thermal structure variation in a porous medium when the absorption coefficient of the porous medium that is the most important radiative property, the physical dimension of porous medium and the equivalence ratio of premixed gas mixture are changed. The unsteady radiation model was incorporated in a differential form using the two-flux gray approximation. The maximum value of the conductive heat transfer through both gas phase and porous medium was found to be less than 6% compared with that of the radiative heat transfer. The reaction zone shifted upstream and the flame thickness decreased as either the geometrical length of porous medium increased or the absorption coefficient decreased.