This paper presents 2D simulations of the dynamics formation a nanosecond spark discharge between two point electrodes in air at atmospheric pressure 300 and 1000 K, induced heating following hydrodynamic expansion. As first step, we have considered that 30% energy instantaneously heats ambient air. At end voltage pulse, it is shown density temperature distributions are non-uniform interelectrode gap. Rapidly after cylindrical shock wave formed propagates with velocity very close to speed...

This paper presents simulations of an air plasma discharge at atmospheric pressure initiated by a needle anode set inside dielectric capillary tube. We have studied the influence tube inner radius and its relative permittivity ε r on structure dynamics. As reference, we used = 1 to study only cylindrical constraint discharge. For 100 µm 1, shown that fills during propagation is rather homogeneous behind front. When in range 300–600 µm, tubular with peak values electric field electron density...

This paper presents an experimental and numerical study of a pulsed air plasma discharge at atmospheric pressure propagating in capillary glass tube. In this work, we have compared the structures axial propagation velocities discharges. First, studied needle-to-plane configuration without For applied voltages range 7–18 kV, observed experiments simulations that ball starts to develop around needle tip. Then, for less than 14 experiments, rapidly splits into several streamer channels with...

This paper presents simulations of the dynamics nanosecond repetitively pulsed discharges between two point electrodes in atmospheric pressure air at 300 and 1000 K. At K, preionization left by successive end interpulses mainly consists positive negative ions with a density about 109 cm−3 for repetition frequency 10 kHz. When photoionization is taken into account level seed charges cm−3, characteristics discharge during voltage pulse are shown to depend only weakly on nature (electrons or...

This paper presents simulations of the dynamics air discharges between two point electrodes at atmospheric pressure for different gas temperatures 300 and 1000 K. Simulation results show that in early stages glow regime, streamer propagate gap form after their connection a conducting channel electrodes. In recent experimental work on nanosecond repetitively pulsed (NRP) K with an interelectrode distance 5 mm, it was found regime is obtained if average electric field least equal to breakdown...

This paper presents 2D simulations of nanosecond discharges between two point electrodes for four different H2–air mixtures defined by their equivalence ratios ϕ (i.e. , air, lean mixture, stoichiometric mixture and rich mixture) at atmospheric pressure an initial temperature 1000 K. In a first step, we have shown that the composition has only very small influence on discharge dynamics structure during streamer phase up to formation plasma channel in with . However, as is formed slightly...

This paper presents 2D simulations of nanosecond repetitively pulsed discharges in air at atmospheric pressure coupled with a model the external electrical circuit used experiments. Then, during discharge, voltage applied to electrodes varies time as function dependent value plasma channel conductivity. In this work, we have simulated several consecutive between two point initially 1000 K frequency 10 kHz. First, three spark discharges. We shown that temperature increases significantly pulse...

Abstract Direct current (DC) electric arcs are of particular interest because they can produce large volumes thermal plasmas with controlled energy deposition. When such discharges applied in a gas flow, convection displaces the top arc downstream while roots remain attached to electrodes, thus increasing length over time. However, this growth is limited by restrike phenomenon, which starts from streamers appearing high field regions and shortcutting long, stretched arc. From numerical point...

Abstract The dynamics of a nanosecond positive ionization front generated in pin-to-plane geometry atmospheric pressure air is simulated using 2D axisymmetric drift-diffusion fluid model. For 16 mm gap and sharp pin electrode, the plateau applied voltage varied between 40 60 kV rise time 0.5 1.5 ns or DC applied. discharge ignition at are shown to depend mostly on time. connection time, i.e. for wave ignite, propagate connect plane strongly both values all cases, has conical shape with...

For many applications of atmospheric pressure plasmas, a crucial issue is to obtain glow discharges at 300 K. We have generated such plasmas with nanosecond repetitively pulsed method. present experimental and simulated optical emission images the dynamics formation regime early stages its development.

View Video Presentation: https://doi.org/10.2514/6.2022-0831.vid Plasma-assisted combustion (PAC) is a promising technology that could lead to breakthrough in propulsion systems. Many plasmas can be used for such applications. Among them, DC electric arcs are interesting because they produce large volumes of thermal with controlled energy deposition. When discharges applied gas flow, convection entrains the head arc downstream while its feet remain attached electrodes, thus increasing length...

The experimental and simulated optical emissions of an air discharge at atmospheric pressure propagating in a capillary glass tube are compared for two radii: 100 300 <formula formulatype="inline" xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"><tex Notation="TeX">$\mu\hbox{m}$ </tex></formula> . For Notation="TeX">$\mu\hbox{m}$</tex></formula> , both calculated show tubular structure the discharge. Notation="TeX">$ \mu\hbox{m}$</tex></formula>...

Abstract A numerical parametric study on positive diffuse discharges in point-to-plane geometry air at atmospheric pressure is presented. Different discharge characteristics are studied: ignition time, connection time to the grounded cathode plane, shape of and its maximum radius evolution electric field front velocity ionization during propagation. First, a case DC voltage 50 kV applied rod anode ended by semi-sphere with 100 μ m set 1.6 cm from plane considered. The influence radius,...

In this study, the interaction of an aeronautic skin with a lightning stroke during pulsed arc phase has been focused. The effect material is emphasized by varying its conductivity while maintaining constant thickness. Three different values electrical are considered, corresponding to two resistive carbon skins, and conductive aluminium skin. Numerical simulations carried out 2D axi-symmetric finite-volume compressible MHD code, including Joule heating, Laplace forces radiative fluxes....

The interaction between a glow discharge and the bow shock of Mach 3 air flow around truncated conical model with central spike is modeled, comparison made prior experimental results. KRONOS workflow for plasma modeling in fields, which has recently been developed at ONERA, was used modeling. Based on quasi-neutral approximation, it couples hypersonic reactive fields electron chemistry, including effect non-Maxwellian energy distribution function. involves 12 species 82 reactions,...