Direct thrust test and asymmetric performance of porous ionic liquid electrospray thruster  

作　　者：Yuntao GUO Wei SUN Zhenning SUN Zhiwen WU Jianwu HE Chao YANG Ningfei WANG 

机构地区：[1]School of Aerospace Engineering,Beijing Institute of Technology,Beijing 100081,China [2]Beijing Institute of Electronic System Engineering,Beijing 100039,China [3]Key Laboratory of Microgravity,Institute of Mechanics,Chinese Academy of Sciences,Beijing 100190,China [4]School of Engineering Sciences,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Journal of Aeronautics》2023年第4期120-133,共14页中国航空学报（英文版）

基　　金：supported by the National Key R&D Program of China(No.2020YFC2201103).

摘　　要：In order to meet the demand of CubeSats for low power and high-performance micro-propulsion system,a porous ionic liquid electrospray thruster prototype is developed in this study.1010 conical emitter arrays are fabricated on an area of 3.24 cm^(2) by computer numerical control machining technology.The propellant is 1-ethyl-3-methylimidazolium tetrafluoroborate.The over-all dimension of the assembled prototype is 3 cm×3 cm×1 cm,with a total weight of about 15 g(with propellant).The performance of this prototype is tested under vacuum.The results show that it can work in the voltage range of±2.0 kV to±3.0 kV,and the maximum emission current and input power are about 355 lA and 1.12 W.Time of Flight(TOF)mass spectrometry results show that cationic monomers and dimers dominate the beam in positive mode,while a higher proportion of higher-order solvated ion clusters in negative mode.The maximum specific impulse is 2992 s in positive mode and 849 s in negative mode.The thrust is measured in two methods:one is calculated by TOF results and the other is directly measured by high-precision torsional thrust stand.The thrust(T)obtained by these two methods conforms to a certain scaling law with respect to the emis-sion current(I_(em))and the applied voltage(V_(app)),following the scale of T-Iem_(Vapp)^(0.5),and the thrust range is from 2.1 lN to 42.6 lN.Many thruster performance parameters are significantly different in positive and negative modes.We speculate that due to the higher solvation energy of the anion,more solvated ion clusters are formed rather than pure ions under the same electric field.It may help to improve thruster performance if porous materials with smaller pore sizes are used as reservoirs.Although there are still many problems,most of the performance parameters of ILET-3 are good,which can theoretically meet the requirements of CubeSats for micro-propulsion system.

关 键 词：Asymmetric performance Direct thrust test Ionic liquid electrospray thruster Time of flight mass spectrometry Torsional thrust stand 

分 类 号：V439[航空宇航科学与技术—航空宇航推进理论与工程]