Investigating Wire Ablation Dynamics in a Modified Wire-Fed Pulsed Plasma Thruster

Abstract

Wire-fed pulsed plasma thrusters have been explored as an alternative to traditional solid fuel pulsedplasma thrusters. In continuation of past work, this thesis investigates wire breakdown behavior in an improved wire-fed parallel plate pulsed plasma thruster application, which has been enhanced based on previous iterations. The thruster behavior is compared to a resistance inductance capacitance model that accounts for wire ablation due to resistive heating. A resistive heating model coupled with a circuit model is used to estimate the temperature rise in aluminum wire up to the point of wire vaporization, after which the wire is modeled as a moving plasma sheet. The wire ablation time estimate and model was compared with theoretical predictions over the short and long term using obtained current data. While the model provides a reasonable physical basis, the collected current data did not fully validate the predicted ablation behavior. Strong predicted indicators of plasma transition were absent, and measured values fell short of predicted magnitudes for thruster current. Spectroscopic analysis further indicates energy loss due to ablation of extraneous materials and capacitor failure, which contributed to incomplete wire breakdown. Further investigation, following key redesigns addressing these issues, is suggested.