The Influence Of Regolithparticle Distribution Caused By Collision And Diffusion Under Vacuum Environment

When the Lunar Lander landing on the lunar surface, the engine plume will blowon lunar surface, craters will appear and regolith particles will be raised. The regolithparticles which in the air will generate a lot of effects for lunar exploration activities,including making visibility drop, destroy the lunar surface to its original state, damageor affect the measurement devices and astronaut spacesuit. Therefore, the study ofregolith particles distribution cased by the interaction between plume and regolithparticles is very important.In this paper, Knudsen number of flow field is calculated according to theory inrarefied gas dynamics on the basis of the preliminary work, and field division isanalyzed in vacuum environment. Using the direct method of Monte Carlo andtracking movement of solid particles unidirectionally coupled method, the distributionof regolith particles in the flow field through Fortran Programming calculation underthe conditions of particle collision has been gotten. In the meantime, the distributionof regolith particles in the flow field has been gotten in the same way under theconditions of mass conservation.Assuming regolith particles are composed of two diameters, the laws ofinfluence of particle distribution due to collision and diffusion have been gotten. Theresults show that the original regolith particles parabolic trajectory has been changedafter considering the regolith particles’ collision. The particle distribution has somerandomness and the "comet tail" shape at the position far from nozzle. It turns out theparticles’ distribution of70micron regolith has the diffusing and upward trend whenmoving far away and formed an obvious peak near the nozzle. However, the diffusionphenomenon of10micron regolith particles is markedly different from the70microregolith particles. This work could be available for lunar research on interactionbetween the plume and regolith particles.