ИСТИНА

Low-temperature nonequilibrium plasma of gas discharges is widely used in many technological processes. In plasma aerodynamics, the generation of controlled plasma areas can be used to reduce dynamic and thermal loads on the surface of an aircraft, to correct the flow regime and to ignite the fuel in the engines. To influence the high-speed flows, it is necessary to know the mechanism of interaction of the shock wave with the plasma region. For nanosecond discharge, a rapid change in the state of the gas occurs, including rapid heating in the energy input region, which leads to the gas-dynamic discontinuities breakdowns at the boundaries of gas and plasma. The shadow visualization and analysis of the flow field after the interaction of pulsed discharges with a plane shock wave inside the discharge volume and outside it give information on the peculiarities of the motion of shock-wave patterns after the discharge. The dynamics of the combined volume discharge of nanosecond duration in the airflow with the plane shock wave was studied. The combined volume discharge with plasma electrodes providing uniform energy input into the gas due to the diffusive form was studied in stationary air and in the gasdynamic flow with a plane shock wave. The presence of shock waves in the discharge volume may change the discharge current regime, the spatial distribution of charged particles, and the radiation structure and duration. Shock wave with Mach number 1.9-4.5 was in the discharge volume or near it while the electric pulse was switched on. The radiation spectra and the discharge currents were registered in the air pressure range 10-150 Torr, a pulsed voltage of 25 kV, and an electric current ~1 kA. It is shown that the electric current duration depends on shock wave position relative to the discharge gap and does not exceed 500 ns at various conditions. Because of discharge energy input, the shock breakdown occurs with the formation of shock waves and contact surfaces. The high-speed shadow imaging was used to study the flow evolution after the discharge pulse. The experimental data on shock waves and contact surfaces positions is is used to determine the energy input during the discharge electric current time.