Characterization of corona-induced ionic wind and spark channel formation using high-speed schlieren imaging

Studying ionic wind is crucial for deepening our comprehension of electrical discharge processes and refining their application in industrial technologies. This research investigates the behavior of needle–needle electrode using high-speed schlieren imaging techniques, focusing on the dynamics of ionic wind and its influence on spark discharge channel formation. Observations indicate that the ionic wind generated during corona discharge provides a structured pathway that significantly guides the development of spark discharge channels, particularly evident in horizontal configurations. Our findings reveal that the velocity and density of the ionic wind increase with decreasing curvature radius of the needle tip, thereby enhancing its guiding effect. Furthermore, the spark discharge channel forms through the convergence of positive and negative streamers, which meet near the cathode, leading to substantial disturbances in the surrounding flow field post-discharge. This research highlights the intricate relationship between corona and spark discharges, demonstrating the critical role of ionic wind in influencing discharge channel morphology and offering insights for future applications in plasma and electrostatic-based technologies.