Theoretical Analysis of Oscillatory Burning of Homogeneous Solid Propellant Including Non-Steady Gas Phase Effects

Abstract

Abstract This paper presents a theoretical analysis of the linear burning response of an homogeneous solid propellant to pressure fluctuations. The major contribution of this work is to take into account the non-steady effects of the gas phase in a systematic way and thus, eliminate the strong limitation of previous analysis in which the gas-phase is assumed to respond in a quasi-steady manner. Two different response mechanisms are exhibited depending on the frequency range. In agreement with the well known quasi-steady theory, the low frequency response is mainly controlled by the thermal relaxation in the solid phase and is triggered through the pressure dependence of the prefactors in the pyrolysis and burning laws. At high frequencies, the gas temperature fluctuations associated with pressure oscillations, are shown to introduce a new response mechanism of the burning rate independent of the pressure exponents. This response mechanism involves the structure of the gaseous flame. The resulting vibrator...