Critical Parametric Studies of Combustion Instability in Solid Rocket Motors

Vortex shedding, combustion response and damping can cause combustion instability under some conditions. In this paper, several mechanisms that cause combustion instability, including the geometry of the solid rocket motors (SRMs), the combustion response of the propellant, particle damping, and nozzle damping, are investigated. Specifically, the influence of the slot of the grains on the chamber acoustic mode, the content of aluminum on the combustion response and particle distribution, and the nozzle throat diameter on the nozzle damping are parametrically analyzed, respectively. Moreover, the critical parametric test in the SRM with a large length-to-diameter ratio is carried out. The results prove that the evaluation method promoted in this study can be used in the prediction of combustion instability in the SRMs.