The production process of OH radicals in an atmospheric-pressure streamer discharge is studied. A model developed to analyse the characteristics a pulsed positive point-to-plane electrodes filled with humid air at atmospheric pressure. results indicate that behaviour and after pulse characterized by three reaction processes: ‘OH-production’, ‘OH-cycle’ ‘OH-recombination’. first OH-production includes dissociation reactions H2O O(1D) N2 , which are main processes discharge. Immediately...

In this study, we present the development of a compact and lightweight nanosecond pulsed power supply designed to improve performance plasma actuators for flow control on unmanned aerial vehicles (UAVs). While traditional AC supplies are commonly used in actuators, offer advantage operating over wider range Reynolds numbers, making them highly desirable. However, miniaturization weight reduction pose significant challenges. To address these issues, novel approach using high-voltage silicon...

The effect of pulse rise rate on a streamer discharge is investigated through both experiments and simulations. Pulsed voltages with 0.11–0.52 kV ns−1 are applied to point-to-plane electrode configurations, the effects observed from ICCD photographs. emission light simulated by previously developed two-dimensional simulation model, results compared experimental results. show that as decreased, there decrease in current, velocity primary streamer, diameter channel length secondary streamer....

Gas heating in an atmospheric-pressure streamer discharge was analysed by a two-dimensional simulation model describing internal molecular energy transfer. Our incorporates concepts from the fast gas mechanism proposed Popov (2011 J. Phys. D: Appl. 44 285201) and our self-developed state-to-state vibrational kinetics. In dry air, occurs mainly electron-impact dissociation reactions of O2 molecules quenching processes electronically excited N2(B 3Πg, C 3Πu) O(1D) atoms. humid rapid...

The azimuthal plasma current in a magnetic nozzle of radiofrequency thruster is experimentally identified by measuring the plasma-induced field. axial momentum increases over about 20 cm downstream exit due to Lorentz force arising from current. measured shows that given sum electron diamagnetic drift and currents, where latter component decreases with an increase field strength; hence approaches one for strong calculated radial smaller than directly exerted field, which indicates existence...

Electrohydrodynamic (EHD) force is used for active control of fluid motion and the generation propulsive thrust by inducing ionic wind with no moving parts. We propose a method successively generating accelerating induced surface dielectric-barrier-discharge (DBD), referred to as DBD plasma actuator multiple electrodes. A conventional fails generate unidirectional wind, due counter ionic-wind electrodes actuator. However, can be obtained designing an applied voltage waveform electrode...

Abstract A streamer discharge model is developed to analyse the characteristics of a pulsed positive in point-to-plane electrodes filled with oxygen–nitrogen mixed gas at room temperature and atmospheric pressure. In this paper we study mechanisms O N radical production an atmospheric-pressure discharge. To confirm validity simulation model, emission light current are compared experimental data several voltages mixtures 2–20% oxygen concentrations. The calculated streak picture axial...

The interaction between the gas-heating phenomenon in a pulsed discharge atmospheric-pressure air and separated shear layer flow around airfoil is discussed. first half of paper details development modeling for gas heating reviews recent research results. Particular attention paid to processes fast slow heating. In latter paper, experimental results high-speed Schlieren visualization are presented nanosecond-pulse-driven dielectric-barrier-discharge plasma actuator (ns-DBDPA) actuation...

Momentum exerted to a lateral wall of helicon plasma source is individually measured for argon, krypton, and xenon gases. A significant loss the axial momentum wall, which has been assumed be negligible, experimentally identified when an axially asymmetric density profile formed in source. This indicates that radially lost ions deliver not only radial but also wall. The formation asymmetry causing interpreted with competition between magnetic field neutral depletion effects.

Thrust imparted by a helicon plasma thruster is experimentally measured for two different diameter source tubes. The measurements demonstrate that the thrust-over-power of can be increased enlarging diameter. This result qualitatively understood with simple analysis connecting global model in and one-dimensional magnetic nozzle model, where does not include field effect cross-field diffusion nozzle. A mass flow rate propellant argon strength are surveyed; then thrust ∼18 mN obtained rf power...

Abstract In this study, the temporal variation of an electric potential distribution was measured in a surface dielectric barrier discharge experiment using Pockels effect. A branching pattern and homogeneous were respectively observed when positive negative voltages applied. When continuous alternating current applied to electrode, spatial distributions significantly changed between first subsequent cycles. The results indicate that electrostatic repulsive forces caused by residual charges...

Abstract Limited research has been conducted on the formation mechanism of chemically active species in streamer discharges with respect to oxygen concentration, which is critical various applications such as ozone generation, air purification, and plasma-assisted combustion, among others. Herein, concentration an N 2 /O gas atmosphere varied from 1% 99% under atmospheric pressure room temperature investigate changes characteristics discharge propagation generation species. As increases 10%...

Abstract Dielectric barrier discharges (DBDs) using atmospheric pressure plasma are utilised in various industries, including environmental remediation, semiconductor manufacturing, and energy technology. It is crucial to understand regulate their properties for technological optimisation. Of particular significance the surface charge generated by DBDs, as it primary physical factor that determines electric field plasma, resulting overcurrent suppression radical formation. This study...

Momentum, i.e., force, exerted from a small helicon plasma thruster to target plate is measured simultaneously with direct thrust measurement using balance. The calibration coefficient relating displacement steady-state force obtained by supplying dc coil mounted on the target, where acting permanent magnet located near directly load cell. As flow in good agreement thrust, validity of technique demonstrated under present operating conditions, operated steady-state. Furthermore, swing...

Production of chemically active species in primary and secondary streamers is investigated using a two-dimensional axisymmetric numerical simulation model. The production processes N2(v = 1), O(3P) N(4S), which each have different threshold energies, are simulated experimentally obtained pulsed voltages with peak values, Vpeak, 18, 24 30 kV dry air at atmospheric pressure. As Vpeak increases, the length streamer although there little change characteristics. This means that ratio phase to...

Gas-density perturbations near an airfoil surface generated by a nanosecond dielectric-barrier-discharge plasma actuator (ns-DBDPA) are visualized using high-speed Schlieren imaging method. Wind-tunnel experiments conducted for wind speed of 20 m s−1 with NACA0015 whose chord length is 100 mm. The results show that the ns-DBDPA first generates pressure wave and then stochastic gas density leading edge airfoil. Two structures different characteristics observed in perturbations. One structure...

An electron energy probability function and a rf magnetic field are measured in hydrogen helicon source, where axial transverse static fields applied to the source by solenoids diffusion chamber filter magnets, respectively. It is demonstrated that wave reflected rapidly bent resultant standing heats electrons between filter, while cooling effect maintained. interpreted generated presence of spatially localized change refractive index.

Abstract Gas density perturbations generated by an alternating-current dielectric-barrier-discharge plasma actuator (ac-DBDPA) are quantitatively visualised using the background-oriented schlieren (BOS) method. A method of setting optimum boundary condition for solving Poisson equation in BOS is studied, and integration vicinity where change steep proposed. The applied two cases with different voltage amplitudes, variation absolute value discussed discharge properties. results show a...

Wind tunnel experiments at a flow velocity of 40 m s−1 with nanosecond-pulse-driven plasma actuator (ns-DBDPA) on an airfoil have been performed (i) to study discharge parameters inducing the ns-DBDPA control effect and (ii) investigate discharge-mediating representing induced discharge-flow interactions. The lift drag forces' measurements demonstrate that, in addition well-known frequency effect, energy per pulse can be key parameter forces rather than power under various raised up 80 mJ...