Experimental study of positive DC corona discharge in multi-tip electrodes for ionic wind-based thrusters

Electroaerodynamic (EAD) thrusters utilize corona discharge to generate ionic wind, thereby directly converting electrical energy into mechanical energy. These thrusters feature significant advantages, including structural simplicity, rapid response, and the absence of moving parts, making them highly suitable for applications in small satellites and unmanned aerial vehicles. This paper experimentally investigates the ionic wind characteristics of multi-tip sawtooth-ring electrodes under positive DC corona discharge. The study focuses on how varying tip numbers (N = 10, 20, and 30) influence flow dynamics, electrical and optical properties, and thrust performance. Particle image velocimetry, high-precision thrust measurements, and electrical and optical diagnostics are utilized to analyze the relationship between electrode geometry and ionic wind performance. Results indicate that increasing the tip number significantly enhances corona discharge performance: the onset voltage for ionic wind decreases, while the discharge current, ionic wind velocity, and thrust increase accordingly. Specifically, as the tip number increases from N = 10 to N = 30, the corona inception voltage drops from 13.33 kV to 10.93 kV, and the peak ionic wind velocity rises to 1.45 m s⁻¹—a 35.5% increase. The maximum thrust achieved reaches 7.04 mN at 20 kV. The thrust-to-power ratio peaks between 14 and 16 kV. Compared with conventional wire-tube electrodes, the sawtooth-ring electrode demonstrated higher thrust output and maintained a compact geometry under identical applied voltages. These findings provide experimental data and theoretical understanding that can support further optimization of electrode designs for EAD thrusters. Future work may explore multi-stage thruster configurations and broader operational conditions to further improve thrust performance and assess the applicability of ionic wind propulsion in aerospace contexts.