Numerical Analysis for the Design Optimization of Sawtooth-Shaped Channels for Enhanced Reverse Flow Control

This study investigates the effects of anode geometry on neutral flow dynamics in a Hall thruster with an anode layer (TAL) using argon propellant, aiming to enhance performance by optimizing anode geometry. To enhance propellant utilization efficiency, four key geometric parameters of an anode wall with a triangular groove structure—slope orientation, anode length, inclination angle, and groove depth—were evaluated using the Direct Simulation Monte Carlo (DSMC) method. The results indicate that reverse-facing slopes enhanced local neutral density near the ionization region, and shallower grooves with steeper angles promoted stronger backflow and neutral confinement, leading to a maximum density increase of up to 21.68% compared to a conventional flat, straight anode. Additionally, shorter anode lengths increased neutral density closer to the ionization region, while the neutral density distribution inside the ionization region tended to converge to a similar profile despite varying anode lengths. These findings are expected to provide design guidelines for optimizing anode geometry to effectively control neutral density and enhance performance in Hall thrusters using alternative propellants like argon.