S.N. Chuvashev

Probe Diagnostics of Gas Discharges in Supersonic Airflows

A new case of probe diagnostics of plasma density under the condition typical for plasma aerodynamic applications (high voltage and electric e eld, high nonequilibrium between components, high gas pressures, and a considerable compression effect ) has been examined. The experiments have been carried out in dc and pulsed periodic discharges in supersonic aire ows with Mach number M = 2 at the static ambient pressure range 10 ‐200 torr. A personal-computer controlled double probe with an optogalvanic isolation based on an optocoupler and a e ber optical waveguide have been developed and tested in the gas discharges. A new theory of probe diagnostics of plasmas with a very high electric e eld in a supersonic aire ow is developed based on a computer simulation of the interaction of the probe and the plasma e ow. A combined effect of the e ow compression and the electric e eld perturbation on the plasma density near the probe is revealed. This effect can limit the area of applicability of the probe diagnostics. Measures to prevent this negative effect are suggested. The results of probe diagnostics of the plasma density are in good agreement with those obtained using the microwave interferometer and the spectral method.

The interaction between plasma jet of a capillary discharge and transverse supersonic air flow

An experimental investigation is performed of modes of outflow into stationary air and of supersonic flow of a plasma jet developed by a capillary plasma generator. A theoretical model is suggested, which explains the obtained experimental results and enables one to simulate the process of injection of plasma jet into a supersonic air flow. The possibility is demonstrated of using such jets for the ignition of supersonic flows of combustible mixture.