Numerical Simulation Of Space Plume Impact Effect On Lunar Exploration Vehicle

Studies about vacuum engine plume as well as its knock-on effects are of greatsignificance both theoretically and practically. Generally speaking, our country has along way to go to catch up with foreign advanced laboratories, particularly in certainareas such as the knock-on effects of the plume. With the rapid development of lunarexploration technology, we have entered a field in which the vacuum plume and itsknock-on effects cannot be ignored.Based on previous studies, this paper is going to further study several subjectsassociated with plume. Those are: the2D axisymmetric plume model outside the nozzle;simulation of the knock-on effects of the2D plume; analysis of the impacts of exportvelocity and numberdensity on the wall; simulation of the backflow induced by the2Dplume; analysis of the knock-on effects on simplified3D satellite by the plume.The vacuum plume is an interdisciplinary subject which has association with conti-nuous flow, excessive flow as well as free molecular flow. In this paper, we focus on thestudy of outflow field. First of all we summarize the present study about high-altitude p-lume both at home and abroad. Then we analyze the characteristics and disadvantagesof the existing technology for future works. Finally the direct simulation Monte-Carlo (DSMC) algorithm with Fortran programming language is used to establish the movement and collision module and simulate the plume and its knock-on effects, a high calculation efficiency being achieved.Drawing Processing based on data result obtained by post-processing softwareTecplot, and the analytical results shows temperature, density and pressure in externalplume field decrease rapidly but mach number increases unceasingly with gas flow; themolecule impact number of the wall subjected is proportional to pressure and heat flux;the faster exit velocity is，the more molecule impact number and pressure of the wallsubjected are, contrarily, the less molecule impact number and pressure of the wallsubjected are；the bigger exit density is, the more molecule impact number and pressureof the wall subjected are; the plume impingement that aircraft upper surface closed toengine subjected is serious, and it weakens with the increasing distance; Similarly, theplume impingement that aircraft lower surface where is next to engine subjected is weak,and it strengthens with the increasing distance.