Propagation and quenching of dual-front flames in binary-fuel mixtures

An analytical model was developed for the study of nonadiabatic flame propagation and quenching in binary mixtures of independently reacting fuels. Despite its simple formulation, in which step-wise reactions start at an externally imposed ignition temperature and proceed at a constant rate, the model reproduces the well-known regimes of dual-front propagation: front separation, control, and merging. The results indicate that, depending on the relative concentration of the fuels, the two fronts of the flame may either quench separately – each front at a different level of heat losses in a flame with physically detached fronts – or in unison in a flame with merged fronts. The results of the model are in qualitative agreement with previous experimental tests performed on aluminum–methane–oxidizer mixtures.