Convective combustion of “gasless” systems

A convective mechanism of combustion is proposed to explain the anomalously high burning rate of titanium–soot and titanium–soot–polystyrene “gasless” systems under conditions of one-dimensional filtration of impurity gases. An analysis of experimental and theoretical works shows that the convective mechanism of combustion under conditions of impurity gas release may be ensured by the motion of the melted layer of one of the reagents under the action of the pressure difference of impurity gases. Physical and mathematical models of the process are formulated. It is found that a free volume, which is not occupied by the burden, is necessary for an accelerating regime of combustion. It is shows that the front velocity and the gas pressure increase exponentially at the initial stage of combustion and also if the free volume is greater than the specimen volume. Analytical expressions for the mean convective burning rate are derived. Consideration of the model formulated in the present paper offers an explanation of the differences in the burning laws of “gasless” systems, which are observed in experiments under conditions of counterflow, cocurrent, and two-sided filtration of impurity gases.