Numerical investigation on performance of electrohydrodynamic thruster with needle-ring electrode

The electrohydrodynamic (EHD) thruster is a propulsion system characterized by its propellant-free operation. This paper employs a plasma chemical model to systematically investigate three critical parameters affecting EHD propulsion performance: oxygen concentration, secondary electron emission coefficient (SEEC), and voltage polarity. Results show that optimizing the nitrogen-to-oxygen concentration ratio from 4:1 to 5:1 under positive corona discharge enhances the thrust-to-power ratio by 41.3%. Furthermore, increasing the SEEC from 0.001 to 0.01 produces significant performance improvements, with thrust increasing by 34.5% and thrust-to-power ratio surging by 142.2%. Notably, negative corona discharge exhibits substantially reduced efficiency, as the accumulation of positive charges near the emitter electrode induces aerodynamic resistance, resulting in thrust values less than 1% of those achieved in positive discharge configurations.