Modified Electromechanical Modeling and Parameters Analysis of Magnetoplasmadynamic Thruster

Yu Zhang,Jian Li,Jianjun Wu,Sheng Tan,Yang Ou

doi:10.3390/en12122428

Yu Zhang, Jian Li + Show 3 more

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https://doi.org/10.3390/en12122428

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Journal: Energies	Publication Date: Jun 24, 2019
Citations: 1	License type: CC BY 4.0

Affiliation: National University of Defense Technology

Abstract

To predict the thrust of magnetoplasmadynamic thrusters (MPDTs), a modified electromechanical model was proposed and a comparison with experimental results is presented in this paper. The motion of propellant in the thruster was divided into two portions: the axial motion which was accelerated by the interaction of current and induced self-field, and the swirling motion which was accelerated by the interaction of current and applied magnetic field. The electromechanical model was in good agreement with the experimental data, and the fitting degrees of the model were greater than 0.93. Furthermore, the influence of parameters on the performance of MPDT were investigated by utilizing the electromechanical model. The results indicate that the thrust performance of the thruster improved with the increase of discharge current, anode radius, applied magnetic field strength, and the decrease of mass flow rate. However, the large anode radius and low mass flow rate readily led to the failure of thruster function. Therefore, the model can not only predict the thrust performance of MPDTs, but also guide the design and operation optimization of the thruster.

Highlights

Magnetoplasmadynamic thrusters (MPDTs) are considered as an attractive choice for thrust-demanding space missions, from orbit raising to Mars landing, due to the advantages of low cost, low mass, and high exhaust velocities
Theoretical and experimental studies on MPDTs have been developed for decades, MPDTs presently remain at the fundamental research stage due to the limiting issues of cathode ablation, “onset” phenomenon, and lifetime
A phenomenological or semi-empirical model is still required to predict the performance of MPDTs, and reveal the effect of several parameters on the thrust performance

Summary

Introduction

Magnetoplasmadynamic thrusters (MPDTs) are considered as an attractive choice for thrust-demanding space missions, from orbit raising to Mars landing, due to the advantages of low cost, low mass, and high exhaust velocities. Thrusters with lithium propellant need a more complicated and power-consuming propellant feed system, and vaporized lithium may damage the surface of the spacecraft due to condensation problems [2]. In light of these considerations, extensive research has been carried out on different propellants [3], geometries [4], and applied magnetic field strengths [5,6] in a broad range of power levels. A phenomenological or semi-empirical model is still required to predict the performance of MPDTs, and reveal the effect of several parameters (e.g., discharge current and applied magnetic field strength) on the thrust performance. Several theoretical models have been established for both self-field MPDTs (SF-MPDTs) [2,8,9] and applied-field MPDTs (AF-MPDTs) [5,6,10,11,12,13,14,15]

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