Variation Law and Generation Mechanism of Electromagnetic Rail Muzzle Arc

Electromagnetic railgun launch systems often experience arc discharge at the muzzle and rail erosion during launch due to the effects of transient high currents, which significantly impact their reliability and service life. To investigate the arc changes and ablation mechanisms at the muzzle end of the electromagnetic railgun, this study designed and established an experimental platform for the electromagnetic railgun system. Using a high-speed camera, it captured the real-time changes in the arc morphology at the muzzle during the moment of the armature exiting the muzzle. Additionally, Matlab was employed to perform highlight processing and grayscale layering on each frame of the images, enabling an in-depth analysis of the mechanisms underlying the formation and propagation of the muzzle arc. The results indicate that the muzzle arc is primarily formed by the combined effects of air medium breakdown and metal vapour ionisation caused by the sudden change in current when the armature leaves the track. It undergoes five stages-arc initiation, expansion, elongation, contraction, and diffusionduring the armature exit process, influenced by multiple factors such as electrical contact damage, high-temperature plasma jets, airflow shear, and changes in the current path.