Three-dimensional distributions of velocity, temperature and pressure in the supersonic air flow at M = 2, as well as the current density in the discharge initiated in it, are obtained. A direct current gas discharge of 10 A is considered in the hydrodynamic approximation within the channel model. The evolution of a transverse–longitudinal discharge is considered in the time range t up to 20 µs. It is shown that the discharge moves almost at the velocity of the main supersonic air flow disturbing it rather weakly. Based on the characteristic values of the current density and gas temperature of 8000–10 000 K obtained in the calculations, the electron density in the discharge channel is estimated as ne ~ 1016 cm–3. The field strength of E ~ 125 V/cm is estimated and the reduced field strength in the discharge channel E/N is about 30 Td. In the configuration of an aerodynamic model with shortened electrodes, the transition to the discharge phase fixed at their ends is shown.

Steady supersonic air flow in a diverging aerodynamic channel of rectangular cross-section is numerically simulated. The channel represents a laboratory model of an air-breathing straight-flow engine. The aerodynamic model is validated using the experimental data for the case in which the zone of volumetric heat release is absent. After the model has been validated a supersonic flow with a built-in zone of volumetric heat release was numerically simulated. Three-dimensional distributions of the velocity, temperature, and pressure in a steady supersonic air flow are obtained. It is shown that in the case, in which the volumetric density of the heat power of the source is equivalent to the mean total power of the discharge W = 10 kW, the discharge heats the gas up to the temperature T = 1700 to 4200 K, which leads to flow acceleration without its thermal choking. When the thermal power density of the source is equivalent to the mean common discharge power W = 20 kW, the gas is heated more strongly, up to 6700 K, but then local thermal choking of the flow occurs.

The paper presents the results of experimental studies of an unsteady pulsating transverse–longitudinal discharge created in high-speed air and propane–air mixture flows. It is shown that, under the conditions of such a discharge, near the electrodes, the gas is strongly heated, to temperatures of 6000–9000 K, and the gas temperature increases with increasing discharge current and airflow velocity. Test experiments were carried out, the results of which show that, under the conditions of an electrode transverse–longitudinal discharge, quasi-steady non-self-sustained combustion of a supersonic flow of a propane–air mixture is realized.

A nonstationary, transverse-longitudinal electrode discharge was obtained and was generated in a wide variation range of external conditions: the air-flow velocity was varied from 150 to 550 m/s, the minimal interelectrode gap was varied from 0.2 to 0.8 mm, and the maximal pulsating discharge current was varied from 5.5 to 16 A. It is shown that an increase in the discharge current leads to an increase in the maximally attainable plasma channel length and a decrease in the longitudinal electric field and plasma loop pulsation frequency. An increase in the interelectrode gap leads to an increase in voltage across the discharge, the plasma-channel length, and the longitudinal electric field intensity in plasma, whereas the pulsation frequency of voltage across the discharge gap, discharge current, and plasma loop decreases. An increase in flow velocity leads to an increase in electric-field intensity in the plasma and discharge pulsation frequency, whereas the voltage drop across the discharge does not depend on the flow velocity, and the full plasma loop length decreases. It is shown that the addition of propane into the air flow entails an essential change in the dependence of the plasma-loop pulsation frequency on the flow velocity, discharge current, and propane equivalence ratio in the fuel mixture.

The paper presents the results of experimental studies of the parameters of unsteady pulsating transverse–longitudinal discharge plasma created in high-speed airflows. It is experimentally shown that, under the conditions of the discharge under study, the electron density in the channel plasma of a pulsating discharge increases from ~1016 to 4 × 1016 cm–3 with an increase in the discharge current from 4 to 16 A and increases with an increase in the flow velocity at a constant value of the discharge current. It is also shown that the electron temperature in the pulsating discharge plasma is about 1 eV and the channel plasma is a strongly ionized medium, the degree of ionization of which increases from 1 to 30% upon transition from subsonic to supersonic air flows.

The parameters of the plasma of a unsteady, pulsed, transverse-longitudinal discharge generated in subsonic and supersonic air flows are determined. It is shown that the longitudinal electric field strength, as well as the electron density and temperature in the anode part of the plasma loop, exceed the corresponding values in the cathode part of the loop. The effect of the gas flow rate and the discharge current on the electron temperature in the plasma of the pulsed discharge in air and the propane-air mixture is studied.

The results of experimental studies of the fast electron distribution function under the conditions of a nonequilibrium plasma of a pulsed discharge in helium are presented. It is established using various methods that a beam of fast electrons, the energy of which depends on the voltage applied to the discharge gap and gas pressure, is generated at a helium pressure of 0.02–2.0 Torr in the initial stage of the discharge, when the reduced electric field strength exceeds the critical value.

This article presents the results of a series of fundamental studies on a new type of a surface microwave discharge conducted at the Department of Physics of Moscow State University. The discharge is created by a surface wave on a dielectric antenna when powerful electromagnetic radiation in the centimeter wavelength range is supplied to it. The basic properties of a microwave discharge and the spatiotemporal evolution of the parameters of plasma generated by a surface discharge are investigated in a wide range of changes in external conditions.

Under the conditions of a nonstationary pulsating longitudinal-transverse discharge produced in a supersonic cold (T = 175 K) air flow, the combustion of a propane–air mixture has been stabilized. It has been shown that the completeness of propane combustion after stabilization under the conditions of low-temperature plasma amounts to about 95%. The combustion occurs at a flame temperature of 1800–2000 K. A propulsion thrust of about 55 N has been obtained the course of an experiment with plasma-assisted combustion of propane in an expanding channel with a length of 50 cm and a ratio of the inlet and outlet cross sections of S2/S1 = 12.7 at mass flow rates of 105 and 4.9 g/s for air and propane, respectively. This shows good agreement with the value of 60 N calculated under the conditions of complete propane burning.

The plasma parameters of an unsteady pulsating transverse-longitudinal discharge created in subsonic and supersonic air flows are determined. It was shown that in the anode part of the plasma loop, the longitudinal electric field, as well as the electron density and temperature exceed the corresponding values in the cathode part of the loop. The effect of gas flow rate and discharge current on the temperature of electrons in plasma of a pulsating discharge in air and propane-air mixture is also shown.

The influence of the longitudinal distribution of heat release in a supersonic combustion of propane under the conditions of an unsteady pulsed discharge on the gas flow regime in a rectangular channel with a variable cross section is studiecd. It is shown that, with an increase in the mass flow rate of propane, the thrust arising from the supersonic combustion of a lean hydrocarbon fuel in an expanding aerodynamic channel, the pressure jump in the combustion area, and the air temperature in the closed pressure chamber increase. It is revealed that there is a limiting amount of hydrocarbon fuel that can be burned in a supersonic combustion regime in an expanding rectangular aerodynamic channel with side expansion angles α = β = 5° without transition to a subsonic flow, while the ratio of the exit and entry sections S 2 / S 1 is 12.7. The experimental results are in satisfactory agreement with the data of mathematical modeling with allowance for additional heating of the cold supersonic flow in the region of an unsteady pulsed discharge.

The degree of gas ionization in a nonstationary pulsating discharge created using a stationary power source in subsonic and supersonic air streams is determined. It was experimentally obtained that when the flow velocity is changed from 150 m/s to 520 m/s, the plasma electron density near the electrodes (z = 1 cm) varies from 1015 cm-3 to 3.7×1016 cm-3 at an unchanged discharge current of 15.5 A, and the gas temperature rises from 400 K to 1250 K. It is shown that in pulsating discharge plasma the degree of gas ionization is of the order of 10-4 at low subsonic airflow, and with an increase in the flow velocity it increases sharply and reaches a value of 10-2 at velocity of 500 m/s.

In this work the mechanism of occurrence experimentally found out magneto-mechanical effect is offered. The reason of occurrence of rotary movement of micro particles is movement of charges in a spatial layer under action Е× Н fields.

The ionization degree of the plasma in a nonstationary pulsating discharge created by a stationary power source in subsonic and supersonic airflows has been determined. lt was experimentally found that the electron density in the plasma near electrodes varies from 1015 to 3.7 × 1016 cm–3 and the gas temperature increases from 400 to 1250 K when the flow velocity varies from 150 to 520 m/s at a constant discharge current of 15.5 A. It is shown that the gas ionization degree in the pulsating discharge plasma is on the order of l0–4 at low subsonic airflow velocities, while with the increase in the flow rate it increases sharply and reaches the value of 10–2 at the velocity of 500 m/s.