Supersonic flow of a nonequilibrium gas-discharge plasma around a body

The flow of a nonequilibrium gas-discharge plasma around a semicylindrical body is studied. The aim of the study is to see how a change in the degree of nonequilibrium of the incoming plasma changes the separation distance between a shock wave and the body. Experiments are carried out with a supersonic nozzle into which a semicylindrical body is placed. The inlet of the nozzle is connected to a shock tube. In the course of the experiment, electrodes built into the wall of the nozzle initiate a gas discharge in front of the body to produce an additional nonequilibrium ionization in the stationary incoming supersonic flow. The discharge parameters are selected such that the discharge raises the electron temperature and still minimizes heating of the gas. The degree of nonequilibrium of the flow varies with gas-discharge current. Diagnostics of the flow is carried out with a schlieren system based on a semiconductor laser. The system can record flow patterns at definite time instants after discharge initiation.