双脉冲固体火箭发动机隔舱打开与破片运动过程模拟

相比传统固体火箭发动机,具有能量管理特性的双脉冲固体火箭发动机结构更为复杂,为了提高其工作可靠性,针对核心部件金属隔舱的破片运动过程开展了数值仿真与试验研究。首先基于LS-DYNA软件,分析中引入监测函数、逻辑开关函数和加载驱动函数,模拟燃气流对破片的连续作用力,计算得到了在不同时刻破片的空间分布规律、撞击点位置及发动机内部损伤情况,保证了破片运动过程的高保真还原。其次,为了验证仿真结果的准确性,进行了模拟二脉冲初始工况的热流试验,发现破片撞击位置及损伤程度的仿真结果与试验数据一致性较高,其中撞击位置的预示误差小于9%,试验结果充分验证了有限元模型的准确性。由此,建立了适用于双脉冲固体火箭发动机金属隔舱破片运动过程的分析模型,实现了破片撞击位置及损伤程度的高精度预示。

Simulation Analysis on the Opening Process and Movement of Pulse Separation Device in Dual Pulse Motor

Compared with traditional one, dual pulse solid rocket motor with energy management characteristic has more complex structure, which makes it difficult to study its dynamic feature. In order to improve its reliability, numerical simulation and experimental study were carried out for the debris movement process of pulse separation device. Firstly, based on LS-DYNA, monitoring function, logic-switching function and load driving function were used in the analysis to simulate the continuous force of gas flow on debris. With the method above, the spatial distribution of debris at different times, the position of impact area and the internal damage of the motor were simulated completely, which ensures the high fidelity approximation of the moving process of debris. Meanwhile, in order to verify the accuracy of simulation, the dynamic characteristics of the debris were obtained by firing tests simulating the initial operation of the second pulse motor. It was found that the simulation results of the impact location and damage degree of debris were in good agreement with the test, and the prediction error of the impact location was less than 9%, which proved that the model established was correct. Consequently, the model suitable for analyzing the whole moving process of pulse separation device of dual pulse solid rocket motor was systematically proposed.