Numerical simulation of influence of anode current density distributions on anode melting pool flow in high-current vacuum arc subjected to axial magnetic fields

In order to investigate the formation reason and influence factors of anode melting pool rotation in high-current vacuum arcs (HCVAs) subjected to axial magnetic field (AMF), the rotational symmetric magnetohydrodynamic (MHD) model of anode melting pool flow (AMPF) phenomena in HCVA is established. Based on this model, the influence of different anode current density distributions (ACDDs) on AMPF is simulated and analyzed. Simulation results show that the influence of ACDDs on rotational velocity of AMPF is significant. According to simulation results, the more nonuniform ACDDs can lead to the more rotational velocity. That is to say, the more serious current constriction in HCVA will lead to the larger rotational velocity of AMPF. The changing trend of rotational velocity in simulation results at different moments is in agreement with the experimental observation. Experimental and simulation results both show that the maximal rotational velocity appears at 9-10 ms moments.