A model for macro-performances applied to low power coaxial pulsed plasma thrusters

Pulsed plasma thrusters (PPT), as an important developing direction of micro-satellite propulsion system, are attracting more and more attention. Low power coaxial PPT has great advantages in miniaturization because of its coaxial structure, which is beneficial for micro-satellite applications. Since there are few macro-performances estimation model in low power coaxial PPT, this paper establishes a model based on one-dimensional electromechanical PPT model and gas dynamic pressure forces model to describe macro-performances of low power coaxial PPT. In this model, the electromechanical model describes the plasma electromagnetic acceleration process, current and voltage changes of the main circuit during the discharge process, and the gas dynamic pressure forces model describes the expansion and acceleration of the neutral gas group in the discharge channel. To verify the model, we compared the voltage and current obtained from model simulation with the experimental results, and compared the impulse bit measured in the experiment with the impulse bit calculated by the model. The results show that the model established in this paper can well simulate the variation of voltage and current during the working process of low power coaxial PPT, and can preliminarily estimate the macro performances of the thruster.