Stochastic modeling of multistage combustion of condensed heterogeneous systems

A stochastic model for multistage heterogeneous combustion in condensed systems is developed. Solid particles undergo a chain of sequential reactions A₀ → A₁ → ... → A_M in the combustion wave. A two-dimensional region composed of square cells is considered. Each cell is characterized by temperature and conversion degree, both being random quantities. The probability of the ith reaction in a cell depends on its temperature. The developed model reduces to the classical deterministic model in the case when the correlation between the temperature and the degree of conversion of a cell is neglected. The dynamic behavior of a combustion wave with a two-stage sequential reaction is examined by computer simulation. When the reaction fronts are separated they can demonstrate different patterns of dynamic behavior, for example, two waves of spinning combustion. When the first reaction, which has a lower activation energy, is controlled by heat flux from the zone of the second reaction, a jump-like propagation of the combustion wave has been observed for a certain set of parameters. The results of computer simulation agree qualitatively with experimental data for a number of systems.