Research On Interaction Mechanism Between Martain Dust And Spacecraft Based On DEM-CFD Method

Martian dust is a strongly adherent material covering the surface of Mars.That can easily deposit on the surface of the detector or enter the gap between the detector structure and the mechanism,decreasing the power of detector solar panels and resulting in friction and wear of structures.At present,there have been several Mars probes that couldn’t function properly due to the drop of deposited Martian dust.Therefore,it is of great significance to study the accumulation of Martian dust particles on the surface of the spacecraft and the removal of Mars dust.In this paper,based on particle contact mechanics in discrete element,the accumulation of Martian dust particles on the surface of spacecraft and the removal of Martian dust particles under high-velocity airflow are studied.Analyzed the adhesive energy loss and damping energy loss during Martian dustspacecraft collision and Mars dust-particle bed collisions based on discrete element theory.Then,established the theoretical model of critical cumulative wind speed for Martian dust particles based on energy loss and study the cut-off effect of the critical cumulative wind speed according to the change of the restitution coefficient.Finally,the effects of particle size and collision parameters on the critical cumulative wind speed of Martian dust were analyzed,and the random model for the critical cumulative wind speed of the Martian dust particles.Established a mathematical description of the contact state of Martian dust – spacecraft contact and Mars dust-particle bed contact.Then,by analyzing the van der Waals force,electric force and fluent force of Martian dust when contacting with spacecraft and particle bed,the conditions for starting the Martian dust particles and the critical start-up wind speed theoretical model are established.Finally,the influence of various parameters on the critical start-up wind speed of Martian dust particles was analyzed.Finally,a random model of the critical start-up wind speed of Martian dust was established.Through the image analysis of Martian dust,typical particle shapes of Martian dust particle was selected and the discrete element model of the Martian dust particles was established based on the cluster particle method.The DEM-CFD model for the cumulation and start-up of Martian dust particles was established,and wind tunnel experiments were performed to match the parameters of the simulation model.The cumulation and start-up simulations of Martian dust particles of different particle sizes and shapes were performed,get the cumulation rate andremoval rate and analyzed the error between simulation results and theoretical results.