Influence of propellant injection directionality on the performance of an argon Hall thruster

The performance characteristics of an argon propellant Hall thruster with two types of propellant injectors, the axial and swirl injectors, were investigated. In the swirl injector, the propellant is injected in the tangential direction. At a discharge voltage of 150 V, the swirl injector achieved a higher propellant utilization efficiency (30.3%) and anode efficiency (8.8%) compared to the axial injector (26.7% and 7%, respectively). A numerical simulation quantitatively explained the reason for these differences, which shows an increase in the neutral particle density of 32.6% near the injection region and 7.8% at the exit of the hollow anode with the swirl injector. Neutral particle accommodation on the anode wall was found to be the predominant mechanism, which reduces the injection effect.