Numerical simulation of the effect of multiple factors on the ignition process of a solid rocket motor

With the continuous development of manned space technology, higher requirements have been proposed for solid rocket motors. The ignition process of solid rocket motors affects the reliability, stability and safety of their operation. The ignition powder, cover opening pressure and grain length‐diameter ratio are the main factors affecting the ignition process. Therefore, the influence of different factors on the ignition process of solid rocket motors is studied with numerical simulations. Based on the finite volume method, the ignition process of a solid rocket motor is modelled and experimentally verified. Then, the pressure and temperature distribution characteristics during the ignition delay, flame propagation and gas filling times are analysed. Finally, the effects of different ignition powders, cover opening pressures and length‐diameter ratios on the ignition process are compared and analysed. The results show that the model has high prediction accuracy. When the ignition powder is 6 g, the maximum combustion temperature of solid rocket motor increases from 2590 K to 2620 K between 0.1 ms and 0.44 ms. Between 0.44 ms and 3.18 ms, intermittent flame propagation and pressure oscillations occur. In the gas filling time, the flow field gradually stabilizes. Increasing the ignition powder mass is beneficial to the ignition process, but the disadvantages of pressure oscillations should be considered. Increasing the cover opening pressure enhances the ignition process, while increasing the length‐diameter ratio increases the ignition pressure building time. The study results provide technical support for the structural design of solid rocket motors.