Finite volume simulation of arc: pinching arc plasma by high-frequency alternating longitudinal magnetic field

Abstract: Arc plasmas have promising applications in many fields. To explore their property is of interest. This paper presents detailed pressure-based finite volume simulation of argon arc. In the modeling, the whole cathode region is coupled to electromagnetic calculations to promise the free change of current density at cathode surface. In numerical solutions, the upwind difference scheme is chosen to promise the transport property of convective terms, and the SIMPLE (Semi-Implicit Method for Pressure Linked Equations) algorithm is used to solve thermal pressure. By simulations of the free-burning argon arc, the model shows good agreement with experiment. We observe an interesting phenomenon that argon arc concentrates intensively in the high-frequency alternating longitudinal magnetic field. Different from existing constricting mechanisms, here arc achieves to be pinched through a continuous transition between shrinking and expansion. The underlying mechanism is that via collaborating with arc's motion inertia, the applied high-frequency alternating magnetic field is able to effectively play a "plasma trap" role, which leads the arc plasma to be imprisoned into a narrower space. This may provide a new approach to constrict arc.