飞船返回舱水上回收的冲击响应和入水姿态分析

Impact response and water entry posture of a Space Capsule's water recovery

飞船返回舱在入水的初始阶段遭受较大的冲击载荷,严重影响返回舱的结构安全和内部人员安全。基于NASA的试验模型,运用LS-DYNA软件中流固耦合算法对返回舱的入水过程进行了数值模拟。分别讨论了垂直入水和带有水平速度入水情况下返回舱的动力学响应,计算得到的加速度最大值与NASA的试验数据吻合。在此基础上,分析了返回舱以不同入水倾角,不同质量和不同入水姿态情况下的结构响应,发现入水倾角和质量越大,返回舱的加速度值越小。在考察不同姿态入水的情况中,正向倾斜入水时加速度最大值比负向倾斜小;质心在下的加速度最大值比质心在上的大。负向倾斜质心在下的情况,返回舱入水后姿态稳定性更好。

At the beginning of its water entry, a space capsule suffers a big impact load, it has an important effect on the safety of the capsule structure and people inside. Base on NASA＇ s experimental model,The process of the capsule water entry was simulated with the fluid-structure interaction algorithm in the software LS-DYNA. The dynamic responses of the capsule were discussed in the vertical and horizontal directions, respectively. The simulated maximum accelerations agreed well with NASA＇s experimental data. Then, the responses of the capsule were analyzed with different water entry angles, masses and water entry postures. It was shown that the bigger the water entry angle and the mass, the smaller the acceleration of the capsule; for different water entry postures, the maximum acceleration of the capsule with positive incline water entry is smaller than that with negative incline water entry; the maximum acceleration of the capsule in the situation of mass center below is bigger than that in the situation of mass center above; after water entry, the capsule posture is more stable in the situation of negative incline water entry and mass center below.