超高速撞击产生碎片云相分布数值模拟

空间碎片与航天器的撞击速度通常大于10 km/s，这种速度条件下撞击过程的物理特点是高温、高压和高应变率，同时伴随着熔化、汽化及等离子体等相变问题发生。利用AUTODYN/SPH的二次开发功能，在程序中嵌入Sesame状态方程数据库和铝材料的相图，数值模拟出撞击速度为5.0和5.6 km/s时的防护屏穿孔直径分别为9.02 mm和9.34 mm，计算结果与实验结果符合较好，说明物理建模及参数的选取合理，同时也验证了数值模拟方法的正确性及有效性。通过计算给出碎片云的热力学量压力和温度分布，结合铝的相图，对超高速撞击产生碎片云的相分布进行了初步计算，给出了碎片云中固、液、气相的分布范围。

Numerical simulation of phase distribution of debris cloud generated by hypervelocity impact

The impact velocity between space debris and spacecraft is normally in excess of 10 km/s. The impact process at such velocity features high temperature, high pressure and high strain rate, along with phase transitions. The vapor occur at the same time. Based on AUTODYN/SPH secondary development, Sesame EOS library and phase diagram of Al are embedded in the AUTODYN/SPH. The simulated hole diameters of bumpers are 9.02 and 9.34 mm at the impact velocities of 5.0 and 5.6 km/s. The simulation results are consistent well with the experimental results, which shows that the physical modeling and the selection of parameters are reasonable and the method of numerical simulation is correct and valid. The phase distributions of debris cloud generated by hypervelocity impact are computed, and the distribution of gas state, liquid state and solid state in debris cloud is also derived.