Discharge in a Supersonic Gas Flow in the Expanding Region of a Laval Nozzle

Abstract

A theoretical study of a glow discharge in a supersonic gas flow between the central body (cathode) and the nozzle (anode) is carried out. It is a feature of such discharges that the gas-dynamic characteristics change significantly along the gas flow. This refers to the gas pressure, density, and temperature. In such a situation, the discharge location occurs at а place in accordance with the principle of least action. In a supersonic gas flow inside a nozzle, the gas density increases upstream along the central body. Therefore, in accordance with Hehl’s law, the current density increases along the central body. The theoretical model takes these features of the glow discharge into account and calculates the distribution of the internal characteristics of the discharge both along the electric field strength lines and along the stream. Тhe discharge performances in terms of spatial localization, radiation intensity, and formation of near-electrode zones have been established to depend on the magnitude of the current and the geometric parameters of the nozzle and the central body.