Numerical simulation of swirl flow and deformation of the anode melting pool in high-current vacuum arcs subjected to axial magnetic field

Abstract

Vacuum arc under an axial magnetic field (AMF), with the arc current increasing, the anode temperature will exceed the melting point of the anode material. When the anode melting pool is formed, and the rotational plasma of arc column deliveries its momentum to the melting pool, the anode melting pool begins to rotate, which is photographed by some researchers with high-speed camera. In this paper, anode temperature and melting is calculated by the melting and solidification model, swirl flow of the anode melting pool and deformation of the anode is calculated by the magneto-hydrodynamic (MHD) model with the volume of fraction (VOF) method. Simulation results show that the depth of the anode crater increases with the arc current increasing. Some droplets sputter out from the anode surface. When the deformation and swirl flow of anode melting pool are considered, the anode temperature is not very high and just around the melting point of Cu. Azimuthal velocity of the melting pool is about 2 m/s.