Numerical and experimental investigation of three-electrode air discharge: Propagation characteristics and optimization strategies

Low-temperature plasma technology has demonstrated significant potential for applications such as gas treatment and energy conversion. This study investigates the optimization of a three-electrode discharge system, combining dielectric barrier discharge (DBD) and direct current (DC) discharge at ambient conditions. By experiment and simulation, the effects of electrode geometry, location, and discharge parameters on plasma stability are analyzed. Results reveal that DC-induced pre-ionization plays a crucial role in transitioning from streamer to diffuse discharge, requiring a minimum pre-ionization density of 2×1017 m−3. Smaller electrode diameters enhance the electric field and reactive species densities, while optimized discharge gaps ensure stable and spatial discharge. A minimum voltage of −6 kV (DC) and 3.5 kV (DBD) are necessary for breakdown, with breakdown time decreasing as voltage increases. Power analysis shows dominant energy consumption by the DBD component, emphasizing the need for DBD voltage minimization to improve energy efficiency. These findings provide valuable insights into achieving stable and energy-efficient plasma discharges, offering a foundation for scalable applications in gas treatment and related fields.