Research On Discharge Characteristics Of Hall Thruster With Large Height-diameter Ratio Of Krypton

Hall thruster has the characteristics of high specific impulse and high efficiency,so it has been widely used as the propulsion device of spacecraft.Compared with the xenon working medium widely used in Hall thruster,the Hall thruster using krypton thruster has the advantages of low cost and high specific impulse,but at present,the Hall thruster with krypton thruster generally has the problems of low efficiency,low thrust and difficult to improve.These problems restrict the further development of krypton thruster.In order to increase the thrust of the Hall thruster using krypton,it is necessary to develop a Hall thruster with greater power.If the high power Hall thruster is designed according to the design criteria summarized from the previous research results of the SPT-100 thruster,the thruster will have problems such as large volume,high weight,high cost and so on.At present,this problem seriously limits the scope of application of Hall thruster.The design of high-power Hall thruster is realized by the design method of large height-diameter ratio(height-diameter ratio,that is,the ratio of discharge channel width to middle diameter of Hall thruster).The radial size of the thruster can be greatly reduced and the volume and weight of the thruster can be effectively controlled.and then improve the thrust-weight ratio of the thruster itself and the effective load of the spacecraft.In this paper,the three-dimensional atomic flow field is simulated by comsol free molecular flow module and PIC(2D-3V)simulation.The atomic distribution and discharge characteristics in the channel and plume region of Hall thruster are studied,and the Hall thruster with large aspect ratio of krypton is studied.Firstly,the large aspect ratio Hall thruster is designed on the basis of SPT-100 Hall thruster by using the method of similarity criterion,and the differences in atomic flow field and discharge characteristics between SPT-100 Hall thruster and SPT-100 Hall thruster are compared by simulation.After that,aiming at the problem of insufficient electron conduction capacity of krypton Hall thruster,the large height-diameter ratio Hall thruster under different wall materials was simulated to study the difference of discharge characteristics of krypton Hall thruster under different wall materials.Finally,the large height-diameter ratio Hall thruster of krypton working medium with swirl gas supply is studied,and the difference of large height-diameter ratio krypton Hall thruster before and after adding hydrocyclone is studied.The analysis of the conduction current and discharge characteristics in the simulation results shows that the performance of the krypton Hall thruster is greatly improved with the large aspect ratio design and the introduction of the cyclone,and that the performance of the krypton Hall thruster is best with the Si C material for the krypton Hall thruster.