Abstract A rocket plume impinging on the lunar surface when a lunar lander approaches a landing site can cause significant dust dispersal. This study investigated the near-field rocket plume-lunar surface interaction and subsequent regolith erosion and particle dispersal. These subjects are challenging because of the complicated flow physics associated with the inherently multi-physics multi-scale problem, and the special lunar conditions, characterized by micro-gravity, near-vacuum, extreme dryness, and the unique properties of the regolith. Gas expansion into the near-vacuum lunar condition compared to exhaust gas under terrestrial circumstances varies not only in the shape of plume but also in the pressure profile on the surface. To understand the effect of surface erosion on flow characteristics, in conjunction with the finite volume method of plume impingement of a rocket nozzle, the Roberts erosion model was introduced for the influx mass flow rate of dust particles based on excess shear stress. The particulate phase was then handled in a Lagrangian framework using the discrete phase model. A parametric study on erosion rate was also conducted to examine the effect of particle density, particle diameter, Mach number, and hover altitude. Additionally, the maximum speed and inclined angle of the particles from the surface were computed for various particle diameters and hover altitudes. The resulting information about the pressure and heat flux distribution on lunar module components can be used for engineering design. Finally, high-fidelity simulations of particles eroded from the surface indicated that several scenarios may occur depending on particle diameters, grain-inclined angles from the surface, and hover altitudes.

中文翻译：

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登月过程中近场羽流-地表相互作用和风化层侵蚀和扩散

摘要 当月球着陆器接近着陆点时，撞击月球表面的火箭羽流会导致大量灰尘扩散。这项研究调查了近场火箭羽流-月球表面相互作用以及随后的风化层侵蚀和粒子扩散。由于与固有的多物理场多尺度问题相关的复杂流动物理学以及以微重力、近真空、极端干燥和风化层的独特性质为特征的特殊月球条件，这些学科具有挑战性。与地球环境下的废气相比，接近真空的月球条件下的气体膨胀不仅在羽流的形状上有所不同，而且在地表的压力剖面上也有所不同。要了解表面侵蚀对流动特性的影响，结合火箭喷嘴羽流冲击的有限体积法，引入了罗伯茨侵蚀模型，用于基于超剪应力的尘埃粒子流入质量流量。然后使用离散相模型在拉格朗日框架中处理颗粒相。还对侵蚀率进行了参数研究，以检查粒子密度、粒子直径、马赫数和悬停高度的影响。此外，还计算了各种粒子直径和悬停高度的粒子从表面的最大速度和倾斜角。由此产生的有关月球模块组件压力和热通量分布的信息可用于工程设计。最后，