Analysis on the choosing of test electrode for lightning current metal ablation experiments

Metal ablation area and depth are affected by electrodes used in simulated lightning metal ablation experiment. In this study, electrode materials are firstly investigated to decrease electrode jet. Then nine different shapes of experiment electrodes, which are hemisphere electrode, semi-ellipsoid electrode and cone electrode with three different diameters of 6, 8 and 10mm respectively, are used to investigate the influences on metal ablation results with simulated long continuing current. The results show that, using cone electrode leads to the severest metal ablation results both in ablation area and depth, followed by using semi-ellipsoid electrode and hemisphere electrode. For electrodes of same shape, metal ablation area and depth decrease with its diameter increasing. The different ablation results caused by different shapes of electrodes are properly explained with initial electric field strength distribution analysis, subsequent dynamic electron density and electron energy density distribution analysis by the finite-element numerical analysis software of ANASYS and COMSOL Multiphysics.