Hypersonic vehicles operate at extreme environments at narrow margins of safety. High-speed flight in the atmosphere when volcanic ash and other meteorological particles are present can cause damage to these vehicle surfaces, impairing heat transfer and damaging sensitive components, leading to failure. Upon surveying typical conditions for solid particles that might be encountered, it was determined that A2 test dust is a reasonable representation in terms of particle density, shape, and size distribution. A set of high-fidelity simulations was conducted with a hypersonic forebody to improve our understanding of the particle trajectories and impact energies as a function of particle size at relevant flight conditions. The results indicate that particle sizes between 4 and $100\mu \mathrm{m}$ are responsible for the majority of the net surface-impact energy. It was also found that effects of compressibility and shape on particle drag can be significant within the boundary layer.

高超音速飞行器在极端环境下以狭窄的安全系数运行。当存在火山灰和其他气象颗粒时，在大气中的高速飞行会损坏这些车辆表面，损害传热并损坏敏感组件，从而导致故障。通过调查可能遇到的固体颗粒的典型条件，可以确定A2测试粉尘在颗粒密度，形状和尺寸分布方面是合理的代表。用高超音速前体进行了一组高保真度模拟，以改善我们对相关飞行条件下粒子轨迹和冲击能量随粒子大小变化的理解。结果表明，粒径在4至$100\mu \mathrm{米}$是净表面冲击能量的主要来源。还发现可压缩性和形状对颗粒阻力的影响在边界层内可能是显着的。