A coupled simulation model of the heating process on an anode under high-current vacuum arcs

Anode activity is critical in a high-current interruption process of a vacuum interrupter. Under a high-current arc anode surface temperature may exceed melting point. Under such condition, an evaporation of metal vapor from an anode melting pool may play a role for a failure of the current interruption. The objective of this paper is to develop a 2D axisymmetric numerical simulation model of heat transfer from a vacuum arc column to an anode region under high-current vacuum arc. The model combined both the magnetohydrodynamic (MHD) model of a vacuum arc column and the heat transfer model of an anode region. The model deals with arc plasma behavior of arc column and heat transfer in the anode region in a coupled way. The temperature distribution, plasma pressure and flow velocity are given. The highest temperature on anode surface is about 1750K and appears at about 7ms. The effect of Lorentz force on the flow of arc plasma was significant. It pushed the arc plasma into the central region and affects the pressure distribution. The results can offer detailed information of high-current vacuum arc and its anode phenomena.