Two-step sequential reactions for large activation energies

Abstract

In this article large activation-energy asymptotics are employed to study one-dimensional, steady laminar flame propagation involving a sequential two-step reaction A → B → C. The response of the system is presented in terms of a graph for the burning rate M as a function of the Damköhler numbers D 1 and D 2 of the two reactions. It is found that, in general, there exist two separated flames and the burning rate is controlled by the hotter reaction zone alone. Either reaction may occur first, depending upon the relative magnitudes of the Damköhler numbers and the activation energies. Under appropriate conditions the two flames may either merge, when both reactions are rate-controlling, or spread far apart, when the cooler reaction alone controls.