Analytical study on the structure of radiation controlled flame. 2nd Report, The behavior of the flame in a porous medium.

Abstract

The structure and behavior of radiation controlled flame in a highly porous medium which has a finite length along the flow direction have been clarified in detail through the numerical calculation on the basis of the rigorous treatment for the radiative transfer and of the simplified one-dimensional flame theory. The results demonstrate that the flame is stabilized in the porous medium over a wide range of the mixture velocity. Under the high velocity condition, the gas phase heat conduction is the dominant mode of heat transfer for the flame propagation just as being found in the case of the ordinary flame. On the other hand, under the low velocity condition, the radiation is a significant heat transfer process for the flame propagation in the porous medium. Further, the combustion is enhanced to a considerable extent because of the energy recirculation by radiation heat transfer even if the flame temperature is much lower than that for the ordinary flame.