针栓变推力固体火箭发动机动态响应特性研究

In order to investigate the dynamic response characteristics of the pintle solid rocket motor, based on the adjustable internal elastic model with variable equivalent throat area, the effects of the pintle profile and adjusting process on the dynamic response characteristics of the motor were studied. The results show that the dynamic characteristics for the response time and the thrust response are closely related to the pintle speed, the pintle profile and the propellant pressure index in pintle variable thrust solid rocket motor. The response time is composed of the time of pintle movement and the pressure delay time caused by pintle movement in the motor. With the increase of pintle speed, the relative proportion of the pintle movement and pressure delay process changes, so that the response time first decreases rapidly and then tends to a fixed value, from 32ms to 11.6ms, while the thrust overshoot increases gradually. During the opening process of pintle, the response time is shorter and the thrust overshoot is larger, the calculation shows that the relative variation rate of pressure and equivalent throat area determines thrust overshoot. With the increase of positive pressure index, the variation range of pressure increases, and the thrust overshoot and response time also increase. Compared with positive pressure index, the propellant with negative pressure index significantly shortens the response time and suppresses the thrust overshoot. The convex pintle can also reduce the response time and thrust overshoot at the same time. According to the relative variation rate of the equivalent throat area, the best curvature of the pintle can be obtained to minimize the response time and thrust overshoot.