Influence of Electrode Shape on Performance ofPulsed Magnetoplasmadynamic Thruster SIMP-LEX

Abstract

The pulsed magnetoplasmadynamic thruster SIMP-LEX (Stuttgart impulsing magnetoplasmadynamic thruster for lunar exploration) is developed to serve as a main propulsion system for the lunar mission BW1. Optimizing the thruster's performance is necessary to increase the efficiency and the mean exhaust velocity without increasing the system's mass and energy requirements. Results of experiments varying the flare angle and the gap between the electrodes, the applied voltage, as well as using tongue-shaped or rectangular electrodes are shown and evaluated by means of a statistical approach using Taguchi matrices. Furthermore, an analytical approach toward the influence on the change in inductance along the x axis for these parameters was taken and the resulting performance characteristics are presented. Both tongue shape and flare angle, show a positive effect on the performance, that is, impulse bit, mean exhaust velocity, and thrust efficiency. A maximal I bit is given for a flare angle of ≈20 deg.