DIFFUSION-CONTROLLED SMOLDER PROPAGATION IN A SEMIINFINITE SOLID - THE ASYMPTOTIC TEMPERATURE DISTRIBUTION

The authors consider the steady propagation of a two-dimensional diffu sion-controlled smouldering reaction front parallel to the plane bound ary of a semi-infinite nonporous reactant. The reaction front is assum ed to be a sheet of line heat sources of variable strength. The distri bution of oxidizer concentration and temperature in the porous burnt c har and of the temperature in the reactant is determined in the form o f an asymptotic expansion involving a similarity variable. The tempera ture on the reaction front in the asymptotic region is found to be con stant to high order. The dependence of this temperature on the Lewis n umbers associated with the reactant and the char is found to be in gen eral agreement with observations.