The study on the influence of acceleration on the combustion performance of solid rocket motor

Abstract

Acceleration can cause adverse effects such as abnormal propellant burning rates and irregular interior ballistics in the combustion chamber. To address the issue of solid rocket motors experiencing high accelerations during highly maneuverable flight, this study conducted firing tests on typical solid propellants under acceleration conditions ranging from 0 g to 150 g. A new burning rate model for aluminized propellants in acceleration fields was developed, and the microscopic combustion mechanism of aluminized propellants under these conditions was elucidated. The results indicate that as acceleration increases, the burning rate gain initially increases and then plateaus. The amplitude of burning rate fluctuations significantly exceeds that of pressure fluctuations. Under acceleration conditions of 30 g to 70 g, the interior ballistic curve during the motor's operation phase shows a non-plateau behavior, characterized by an initial pressure increase and subsequent decrease. The retention and agglomeration of aluminum particles on the propellant burning surface were identified as the primary causes of abnormal changes in propellant burning rate and combustion chamber pressure. Simultaneously, the new burning rate model was employed to calculate the burning rate gain ratios under various acceleration conditions, with a maximum value reaching 1.54. The theoretical calculation of the maximum burning rate gain exhibited an error of 4 % compared to the experimental actual values. Additionally, the inner ballistic variation process under different acceleration conditions was predicted, revealing that the theoretically calculated pressure curves were in close agreement with the measured pressure curve trends.