Numerical simulation of an axisymmetric discharge in a supersonic air co-flow

Abstract

The integral and local characteristics of an electric discharge initiated between two coaxial relatively thin conical electrodes are considered. The electrodes are located in an incoming uniform stationary supersonic flow of cold air (M=2, Tg = 167 K, p = 22 kPa) The axis of symmetry of the electrode system is oriented along the flow velocity vector. Numerical simulation of a two-dimensional unsteady flow of thermochemically nonequilibrium air in a self-consistent electric field is performed using the MHD configuration of the PlasmAero package [1] for a nonequilibrium quasi-neutral partially ionized plasma. The evolution of the discharge with a stepwise change in the discharge current from 10 mA to 10 a with the duration of each stage until the practical stabilization of the discharge is achieved is presented. In this case, the discharge passes through stages from a classical glow discharge of moderate pressure to an almost arc discharge, in which, however, the role of field non-thermal ionization is still great, especially near current-carrying spots on the electrodes. The important role of chemical disequilibrium is also noted.