Characteristic features of a barrier discharge occurring on the zhukovskii aerofoil on variation of the surrounding air pressure

Abstract

The results of measuring the jet thrust produced by a dielectric barrier discharge on the Zhukovskii aerofoil are presented. The measurements were made in the pressure range 40-1200 Torr. The maximum velocity of the ion wind attained 4-5 m/s. Based on the analysis of the plasma glow spectrum at a residual air pressure in the vacuum chamber of 40 Torr in the barrier discharge, the values of the temperature T e 2.5⋅10 4 K and of electron concentration N e 2⋅10 15 cm −3 were obtained.Introduction. The dielectric barrier discharge is widely applied in engineering, for example, in the development and engineering design of excimer ultraviolet and vacuum ultraviolet tubes [1], high-power CO 2 lasers [2], and plasma display units [3]. Industrial ozonizers have been developed on its basis [3]. The dielectric barrier discharge is also applied to stabilize flames [4] and improve the properties of polymer films [3].Considerable interest in the world has been directed towards the application of barrier discharge plasmas in aerodynamics. In this field, a study is actively carried out along three basic lines: control of boundary layer separation from the surface of flying vehicles [5][6][7], influence of the dielectric barrier discharge on their aerodynamic resistance [8], as well as reduction of noise level in flight [9].Impressive advances have been made in the field of reduction of aerodynamic resistance of streamlined bodies with an initiated near-surface discharge. The majority of studies were carried out at atmospheric pressure [8,9]; however, with increase in the flight altitude, the atmospheric pressure decreases, and at an altitude of 10,000 m it amounts to about 140 Torr depending on weather conditions. In flights with supersonic velocities, near the flying vehicle surface a region of over-pressure is formed that exceeds the atmospheric one. This has led to a necessity of investigating the influence of the barrier discharge plasma on the aerodynamic resistance in a wide range of pressures. Similar investigations were carried out in various gaseous media such as N 2 , O 2 , He, Ar, Ne, CO 2 , CH 4 , N 2 ⁄ He, N 2 ⁄ Ar, and N 2 ⁄ Ne in the pressure range 0.01-1 atm [10].The results of experimental investigations of the characteristics of the barrier discharge in air in the pressure range 0.2-1 atm are presented in [11,12]. The study of the dependence of the discharge-induced ion wind velocity on the surrounding air pressure carried out with the aid of a Pitot-Prandtl tube at a voltage of 12 and 15 kV and frequency of 1 kHz showed that the maximum value of velocity is attained at a pressure of 0.4 atm and the maximum value of the mass flux at a pressure of 0.6 atm. With further decrease in the pressure, the ion wind velocity decreases.To investigate the shape of the discharge and the dynamics of streamer operation, a photograph of the process with an exposure of 50 ns was made. The photographs obtained showed the linear dependence of the coefficient that determines the rate of the streamer branching length growth on pres...

Diagnostics for characterisation of plasma actuators

“…This can be attributed to changes in high frequency current spikes during the positive half cycle [179]. The power increase trend is followed closely by the plasma extent length as shown by optical imaging [167,177,182], suggesting an increase in the mean free path of particles. As the pressure decreases the discharge transitions from filamentary to diffuse [188].…”

“…This raises the question whether it is better for humidity to be controlled or just measured for this kind of investigations. [176] external airflow 14 1-15 AC-DBD Abe et al (2008) [126] ambient pressure, gas 12-20 1-5 AC-DBD Benard et al (2008) [177] ambient pressure 32 1 AC-DBD Benard et al (2009) [178] relative humidity 32-48 1 AC-DBD Leonov et al (2010) [75] gas 24 0.02-2 AC-DBD Versailles et al (2010) [125] ambient pressure, temperature 15-20.5 10-17 AC-DBD Ashpis and Thurman (2011) [174] air density generic AC-DBD Hollick et al (2011) [179] ambient pressure 12.7 13 AC-DBD Font et al (2011) [128] gas 14-30 0.2 AC-DBD Durscher et al (2012) [117] dielectric temperature 20-46 2-7 AC-DBD Erfani et al (2012) [180] dielectric temperature 2-8 10 AC-DBD Erfani et al (2012b) [181] external flow 15 10 AC-DBD Khramtsov et al (2012) [182] ambient pressure AC-DBD Kriegseis et al (2012) [183] external flow 16-26 8-14 AC-DBD Valerioti and Corke (2012) [184] ambient pressure 11.5-21 1-5 AC-DBD Aba'a Dong et al (2013) [185] dielectric ageing 10 single pulse ns-DBD Nichols and Rovey (2013) [167] ambient pressure 13.4 5 AC-DBD Pereira et al (2013,2014) [123,186] external flow 40 2 AC-DBD Kriegseis et al (2013) [187] external flow 10-28 8-11 AC-DBD Wu et al (2013) [188] ambient pressure 10 23 AC-DBD Kriegseis et al (2014) [189] ambient pressure, external flow 17 9 AC-DBD…”

Numerical investigation of energy deposition in spark discharge in adiabatically and isothermally compressed nitrogen

“…Spark discharge is also used in pulsed light sources. 5) In such sources, a spark discharge is ignited in a gas at an initial room temperature but at high-pressure. For this task, it is important to study the effect of pressure of an isothermally compressed gas on the efficiency of the discharge-to-radiation energy conversion.…”