Influence of externally applied thermal radiation on the burning rates of homogeneous solid propellants

Abstract

A model was developed that describes the thermal interaction of an externally applied radiant energy flux with the combustion zone of a burning homogeneous solid propellant. Under the assumption that there exists a critical zone in which chemical kinetics controls the burning rate, it is shown that the radiation must be absorbed either within this zone or on the cold side of it to augment the burning rate. Conditions necessary for treating the effect of radiation as an increase in initial propellant temperature are identified thereby enabling the temperature sensitivity of the burning rate to be employed for calculating the influence of radiant flux. Roles of stabilizers and of other ingredients are investigated. The burning rate is shown to increase linearly with flux at low radiant intensities and to possibly depart from linearity at high intensities. Comparisons with available experimental results, as well as with results of new experiments reported herein, support the predictions.