A Numerical Simulation Model of Double-Discharge Ablative Pulsed Plasma Thrusters

Abstract

Ablative pulsed plasma thrusters (APPTs) are widely employed as electric propulsion systems for small spacecraft, particularly for orbital maintenance and attitude control missions. However, their performance is severely constrained by late-time ablation (LTA), a phenomenon in which residual heat from the main discharge induces continuous propellant ablation after the pulse terminates, generating unaccelerated neutral particles that account for up to 50% of the total propellant mass loss. To mitigate this fundamental limitation, the double-discharge APPT (DD-APPT) configuration was proposed. In this study, a comprehensive zero-dimensional numerical model is developed to simulate the sequential discharge processes and predict the thruster’s propulsion performance, accounts for the spatial separation of ablation and acceleration regions. Simulation results demonstrate that the optimal energy allocation strategy is to assign 1/8 of the total energy to the primary discharge (for controlled propellant ablation and initial plasma generation) and 7/8 to the secondary discharge (for efficient plasma and acceleration).