Conic Cross-Sectional Electrodes and Their Influence on Negative Corona Discharge and Trichel Pulse Characteristics
Mohammad Hamidieh, Mona Ghassemi
Abstract
This paper computationally investigates the influence of different needle electrodes with conic cross-sections on negative corona discharge. Specifically, the study focuses on Trichel current pulses, a vital characteristic of gas discharge plasma under applied negative DC voltage. The needle cathodes encompass hyperbolic, parabolic, and elliptic shapes, with varying eccentricities while maintaining a constant radius of curvature. The magnitude, frequency, and temporal attributes of Trichel pulses are comparatively and numerically analyzed across a spectrum of eccentricity values. Additionally, a microscopic comparative analysis is conducted on the variations in charged species and electric field distributions for different needle cathode cases. Notably, our findings unveil a significant and consistent trend: Trichel pulse magnitude and frequency exhibit a prominent inverse proportionality with the eccentricity of conic cross-sectional needle cathodes. This trend establishes a distinct sequence in Trichel pulse magnitudes and frequencies, with elliptic needles exhibiting the highest values, followed by parabolic and hyperbolic needles. The negative air discharges are mathematically modeled using a hydrodynamic approach and simulated using COMSOL Multiphysics software. This sensitivity analysis emphasizes the important role of electrode geometry on gas discharge plasma behavior, providing critical insights for optimizing plasma-driven technologies and electrical insulation systems.