发射箱易碎后盖开启过程的数值计算

易碎盖技术在箱式或筒式发射中具有明显的优势，其开启过程涉及冲击波传播及射流运动等复杂的物理现象。利用动网格技术，以固体火箭发动机为研究对象，研究了易碎后盖开启过程，得到了后盖开启过程中流场压强和温度分布，并对开盖过程中燃气射流流场情况进行了分析。结果表明：冲击波在发动机射流径向一定范围内有较高的超压峰值，会对发射装置和周边设备产生破坏作用；后盖运动对燃气射流流动产生了影响，表现为燃气射流随着后盖向下运动而向下方传播的同时，由于受到后盖的阻挡发生反射回流现象；运动过程燃气流冲击作用逐渐变小，除核心区外后盖上的温度和压强也逐渐变小；后盖运动的仿真实验结果与实际试验数据一致，获得了较好相似性。

Numerical Calculation of Opening Process of Frangible Rear Cover of a Launcher

The opening process of rear cover of a launcher involves complex physical phenomena, such as shock wave propagation and jet motion. The dynamic mesh technology is used to get the pressure and temperature distribution of gas jet flow in the process of opening the cover by taking a solid rocket engine as the research object.The opening process of fragile cover is studied, and the gas jet flow is analyzed. The results show that the peak overpressure of shock wave is higher in a radial jet of engine, which may damage the launcher and peripheral equipment; the movement of frangible rear cover has an influence on the gas jet flow. It is shown that the gas jet flows downward with the downward movement of rear cover, and the rear fow of gas jet occurs due to the blocking of rear cover; the shock effect of gas flow decreases gradually in the process of its motion, and the temperature and pressure on the rear cover also decrease gradually except the core area. The simulated results are consistent with the test results.