Research On Numerical Simulation Of Ionic Liquid Electrospray Characteristics And Thruster Design And Beam Diagnosis

The ionic liquid electrospray thruster(ILET)has the characteristics of higher specific impulse and efficiency,large thrust-to-power ratio and simple structure,and can be extended modularly to cover thrusts from the μN to m N scale,making it a high-performance active propulsion system that is highly compatible with the Nano Sat.In this paper,the research work of ILET with higher performance level is carried out on the problems of small charge-to-mass ratio of ILET spray particles and large differences in the working status of emitters,which lead to the performance level being much lower than the theoretical limit value.A phased numerical model of ILET charged particle extraction and acceleration process is established.The two-phase interface control function and dynamic migration rate parameters are introduced to simulate the formation process of Taylor cone of real conductivity ionic liquid,and the simulation of charged particle acceleration process can effectively reflect the influence of operating voltage and extractor geometry parameters on the charged particle transmission rate and beam dispersion angle.An novel emitter material,phase separation borosilicate,with better flow impedance and processing processability,has been developed,which can effectively improve the picosecond laser processing process of geometric parameter consistency between emitters.In view of the problems of poor flatness and complicated processing process,a one-piece extractor design scheme with simple process,higher structural strength and higher flatness is given.Geometric morphological measurements of the emitters(19×19),extractor micropores(19×19)and assembled thrusters using confocal microscopes,the sample area(5 sample areas,61 emitters)with the best machining effect is less than 9μm,and the sample area of the extractor very microporous array(5sample areas,61 micropores)has a height standard deviation of less than 8μm.The Time-of-Flight spectrometer(TOFS)is designed to solve the problem of static interference and capacitive coupling of TOFS under laboratory conditions,and to propose measurement scheme.When ILET operating voltage is ±2k V,the magnitude of the current signal at the collector is about tens of nanoamperes.When an intercept potential(±3k V)is applied by the electrostatic gate,the collector current signal has a significant step change at the rising edge and the falling edge of the interception potential,which can realize the monomers,dimers and trimers in the beam.Quantitative analysis of other main components;beam diagnosis results show that the efficiency of the developed prototype is more than 10% higher than that of other models of ILET.