| The lunar exploration project is one of the most difficult space projects,and its landing and survey missions are easily affected by the dust phenomenon on the lunar surface.Therefore,it is of great value for scientific research and application to explore the characteristics of lunar charged lunar dust.In this paper,the dust mechanism and characteristics of the charged lunar soil on the lunar surface were studied from the perspectives of natural dust and man-made dust.The main research contents and conclusions of this paper are as follows:(1)Based on the influence of lunar dust particle geometry on its charge,Stubbs dynamic fountain model was improved,and the theoretical model of lunar surface electrostatic migration of anomalous lunar dust particles was defined.?When the monthly dust particles are spheroid,regular icosahedron,regular dodecahedron,regular octahedron,regular hexahedron and regular tetrahedron,the correction coefficients of monthly dust particles are1.000,1.065,1.098,1.183,1.241 and 1.490,respectively.?The maximum height of electrostatic suspension of lunar dust is modified,which is 1.5?2 times of the dynamic fountain model and closer to the real value.?The maximum particle radii of the normal tetrahedral lunar dust particles migrating at the subsolar point,the middle region and the twilight line are 0.832 um,0.538 um and 1.594 um,respectively,which are 1.435 times that of the spherical lunar dust particles.(2)The influence factors of lunar dust on the landing pad were systematically analyzed.The discrete element numerical calculation method was adopted to explore the specific influence of each factor on the scope and amount of lunar dust.?The impact velocity of foot pad was positively correlated with the range of lunar dust.The impact load of foot pad is positively correlated with the amount of lunar dust.When the foot pad has impact Angle,the total amount of lunar dust decreases,the range of lunar dust along the direction of velocity component increases,and the range of lunar dust away from the direction of velocity component decreases.?There is a negative correlation between the lunar soil compression modulus and the lunar dust range.There is a negative correlation between the friction Angle of lunar soil and the extent and amount of lunar dust.?The relative density of lunar soil was negatively correlated with the extent and amount of lunar dust.(3)Aiming at the problem of lunar dust at the moment of landing of the lander,a simulation model of lunar dust which can restore the small gravity field and electric field environment on the lunar surface was established.Taking Chang 'e-3 as an example,the actual working conditions are simulated and compared.?The maximum dust heights of spherical,elongated and angular small particles are 35.92 m,45.36 m and 50.21 m,respectively.The simulation results are basically consistent with the calculation results of the lunar dust belt electric quantity correction coefficient in Chapter 2,which verifies the rationality of the value selection.?The maximum dust height is 0.332 m.This simulation result is greater than the reverse result of ren Depeng's laboratory model test,because the influence of particle form on the electric quantity of the lunar dust belt is considered in the simulation model of lunar dust.?At 0.9s after the foot pad of the lander touched the moon,the height of large particles of lunar dust reached the maximum,and the vertical distribution range of lunar dust was 0-0.332 m.Therefore,the minimum ground lift height should not be lower than 0.332 m for the detection equipment with high precision,high sensitivity and susceptible to the disturbance of lunar dust adsorption.?When the foot pad of the lander touched the moon 0.3s later,the amount of large particles of lunar dust reached the maximum,and the vertical distribution range of lunar dust was 0?0.221 m.Therefore,for the detection equipment that is not easy to be absorbed by lunar dust or has little disturbance after absorption of lunar dust,the minimum ground lift height should not be less than 0.221 m.?0?1s after the foot pad of the lander touches the moon,there is a phase of the diffusion of large particles of lunar dust,and the concentration of lunar dust is high.At this time,the detection equipment can take dustproof measures by itself.From 1 to 2.5s after the foot pad touched the moon,the large particles of lunar dust fell back,and the concentration of lunar dust was low.After this,all detection equipment could work normally. |
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