Numerical Simulation of Ignition Transient for Solid Rocket Motors with Large Aspect Ratio

Despite the short duration, ignition transient plays a very important role in the whole operation of a solid rocket motor. A two-dimensional model is proposed to simulate the ignition transient in solid rocket motors with large aspect ratio. Transient mass flow rate inlet is implemented at the inlet of the flow field to simulate the gas from igniter. The temperature of the propellant surface is computed by conduction heat calculation and then is used as a criterion of ignition. Erosive burning is evaluated with Mukunda model. The regression of the burning face is considered, guaranteeing the simulation of the evolvement of erosive burning as the ignition proceeds. The internal ballistics curve obtained from the model meets the experimental data well. The pressure history shows a different trend from that of the burning perimeter, indicating the remarkable influence of erosive burning on the ignition transient. The model proposed in this paper can be used as a reliable approach to simulation of ignition transient for solid rocket motors with large aspect ratio.