Frontal regime of exothermal conversion of refractory condensed compounds

Abstract

We consider a mathematical model of propagation of the combustion front in heterogeneous condensed compounds. For these compounds, the adiabatic combustion temperature is lower than the melting point of the initial reagents and condensed products; it is also lower than the minimum temperature of their eutectics. The chemical interaction in the combustion front is accomplished by a gas transport mechanism due to the gasification of additive oxides. Within the framework of the investigated model, values are obtained for the front velocity, which are of the same order as those observed experimentally. Periodic unstable combustion regimes (fluctuating and spinning) arise when the macrokinetics of the chemical transformation is strongly activated. It is shown that the activation can depend on the gasification energy and, consequently, the evaporation of additive oxides influences the stability of a steady-state combustion regime.