Computation of the self-induced magnetic field in circuit-breaker arcs

This paper applies the computational fluid dynamics methodology to compute arc-flow interaction in circuit breakers. The compressible Euler equations are used as the basic flow model, and source terms are added to represent the ohmic heating, the radiation transport, and the self-induced magnetic pressure in the plasma. The equations are solved by a finite-volume scheme for unstructured triangular grids. Numerical solutions are obtained for a transient 32 kA arc-flow interaction In a geometry investigated experimentally by Jones et al.(1982). The experimentally measured pressure at the cathode tip is compared to computations performed with and without the inclusion of the magnetic pressure term. The importance of these terms for high-current arc-flow interaction cases is confirmed and quantified.