ASYMPTOTIC ANALYSIS OF LAMINAR FLAME PROPAGATION - REVIEW AND EXTENSION

The structure of a steady 1-dimensional isobaric deflagration is analysed in the physical plane for the case of a direct first-order one-step irreversible exothermic unimolecular decomposition under Arrhenius kinetics. In particular, the eigenvalue giving the speed of propagation of the laminar flame into the unburned gas is sought for Lewis-Semenov number unity. Limit-process expansion techniques are applied for the physically interesting limit of activation temperature large relative to the adiabatic flame temperature. Through consideration of the higher-order contributions to the asymptotic solutions for the downstream reactive-diffusive zone and the upstream convective-diffusive zone of the laminar flame, the physical-plane anslysis brings out details of the flame structure, including the two-region character of the downstream zone, not brought out in the conventional phase-plane analysis. Applications of the results of this analysis to more general deflagration problems are discussed. © 1979.