Burning-rate response functions of nitramine-based propellants and HMX from microthermocouple data measurements

The results of experimental burning-rate and burning-surface temperature measurements, which were obtained for nitramine-based propellants and HMX at various pressures and initial temperatures, are used to determine the pressure and temperature sensitivities of the burning rate and surface temperature and the criteria of burning stability. It is shown that the one-dimensional and quasistationary approaches are valid. Based on the data obtained, the functions of burning-rate response to acoustic pressure oscillations are calculated. The estimates of calculation errors show that smoothing of the experimental dependences of the burning rates and surface temperatures allows us to obtain response functions with acceptable errors. The influence of the melted layer on the surface of burning HMX on the stability criteria and the response functions of HMX is taken into account. Introduction of HMX into the structure of catalyst-containing ballistite propellants is found to decrease appreciably the response-function amplitudes. The effect of the propellant structures on these functions is studied.