The 3D simulation of high-current vacuum arc under combined effect of actual magnetic field and external transverse magnetic field

摘要

Based on a steady 3D Magneto-Hydro-Dynamic (MHD) model, the high-current vacuum arc (HCVA) under combined effect of actual magnetic field (MF) and external transverse magnetic field (ETMF) is simulated. The actual MF is generated by cup-type AMF contact system. The ETMF may cause the deflection of arc column which is the main reason of the contact deflected erosion. According to some experimental results, the electron temperature in HCVA is assumed to be uniform and equal to 3eV. So the MHD model is simplified to improve the simulation efficiency. With the three conservation equations (mass, momentum and energy) of ion flow coupling solved, the spatial distributions of some flow parameters can be obtained. The influence of all three components of the magnetic field is inserted by solving the magnetic transport equations sequentially. Proper boundary conditions are set on the cathode and anode side which separated the cathode spots mixing region and anode sheath region from computation domain respectively. Under the influence of the ETMF, the deflection of the plasma flow can be found which may be helpful to understand the mechanism of the contact deflected erosion.