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Lu X.,Huazhong University of Science and Technology | Naidis G.V.,RAS Joint Institute for High Temperatures | Laroussi M.,Old Dominion University | Ostrikov K.,CSIRO | Ostrikov K.,University of Sydney
Physics Reports | Year: 2014

This review focuses on one of the fundamental phenomena that occur upon application of sufficiently strong electric fields to gases, namely the formation and propagation of ionization waves-streamers. The dynamics of streamers is controlled by strongly nonlinear coupling, in localized streamer tip regions, between enhanced (due to charge separation) electric field and ionization and transport of charged species in the enhanced field. Streamers appear in nature (as initial stages of sparks and lightning, as huge structures-sprites above thunderclouds), and are also found in numerous technological applications of electrical discharges. Here we discuss the fundamental physics of the guided streamer-like structures-plasma bullets which are produced in cold atmospheric-pressure plasma jets. Plasma bullets are guided ionization waves moving in a thin column of a jet of plasma forming gases (e.g.,He or Ar) expanding into ambient air. In contrast to streamers in a free (unbounded) space that propagate in a stochastic manner and often branch, guided ionization waves are repetitive and highly-reproducible and propagate along the same path-the jet axis. This property of guided streamers, in comparison with streamers in a free space, enables many advanced time-resolved experimental studies of ionization waves with nanosecond precision. In particular, experimental studies on manipulation of streamers by external electric fields and streamer interactions are critically examined. This review also introduces the basic theories and recent advances on the experimental and computational studies of guided streamers, in particular related to the propagation dynamics of ionization waves and the various parameters of relevance to plasma streamers. This knowledge is very useful to optimize the efficacy of applications of plasma streamer discharges in various fields ranging from health care and medicine to materials science and nanotechnology. © 2014 Elsevier B.V.

Agency: European Commission | Branch: FP7 | Program: CP-FP | Phase: AAT.2013.8-1. | Award Amount: 3.21M | Year: 2013

BUTERFLI is a project in response to the invitation to tender from European Commission FP7 within Call FP7-AAT-2013 RTD-Russia. BUTERFLI is the acronym of BUffet and Transition delay control investigated within Europe-Russia cooperation for improved FLIght performances. The Project Topic will focus on experimental and numerical flow control investigations of different phenomena: the buffet on a laminar airfoil, the buffet on a turbulent supercritical airfoil, and the cross-flow instabilities on a swept wing. Different control techniques will be studied: bump design, fluidic control devices, and DBD devices. The Project aims at the improvement of aircraft flight performances. This Project will be carried out in the framework of a EUROPE RUSSIA cooperation. ONERA is the coordinator, and TSAGI will act as Coordinator of the Russian Parties. There are 12 partners, 7 from Europe and 5 from Russia. ONERA (F), IAG-Stuttgart (G), DLR (G), KTH (S), University of Nottingham (UK), EADS UK Ltd. (UK), TsAGI (Russia), MIPT (Russia), JIHT (Russia), ITAM (Russia), Sukhoi Civil Aircraft (Russia), and Erdyn (F). BUTERFLI is splitted into four work packages: WP1 is dedicated to buffet control on 2D turbulent supercritical wing (tangential jet blowing and plasma actuators) WP2 is dedicated to buffet control on 2D laminar wing (bump and perforation blowing) WP3 is dedicated to crossflow instabilities control on swept wing WP4 ensures the scientific coordination of the overall project, and will proposes final roadmaps for the future.

Naidis G.V.,RAS Joint Institute for High Temperatures
Journal of Physics D: Applied Physics | Year: 2010

The results of a two-dimensional numerical simulation of positive streamer propagation in atmospheric-pressure helium jets injected into ambient air are presented. It is shown that depending on the jet width and the initial radial distribution of electron number density streamer structures of two types can be formed: one with maxima of electric field and electron density at the jet axis and another with maxima of these parameters near the boundary between the jet and surrounding air. The latter structure is similar to the observed ring-shaped structures of plasma bullets. © 2010 IOP Publishing Ltd.

Naidis G.V.,RAS Joint Institute for High Temperatures
Journal of Physics D: Applied Physics | Year: 2011

The results of simulation of positive streamer propagation along a helium jet in ambient air are presented. A two-dimensional axially symmetric streamer model, accounting for variation of helium-air mixture composition in the jet, is used. The obtained distributions of plasma parameters have a ring-shaped structure, typical for plasma bullets. The calculated radial profiles of emitting nitrogen molecules agree with experimental data. © 2011 IOP Publishing Ltd.

Kanel G.I.,RAS Joint Institute for High Temperatures
International Journal of Fracture | Year: 2010

The dynamic tensile strength of materials at load durations of a few microseconds or less is studied by analyzing the spall phenomena under shock pulse loading. The paper is devoted to discussing the methodology and capabilities of the technique to measure spall strength, its error sources, spall fracture of materials of different classes and the factors governing the high-rate fracture of metals and alloys under such conditions. © 2010 Springer Science+Business Media B.V.

Apfelbaum E.M.,RAS Joint Institute for High Temperatures
Physics of Plasmas | Year: 2015

The thermophysical properties of Nickel plasma have been calculated for the temperatures 10-60kK and densities less than 1 g/cm3. These properties are the pressure, internal energy, heat capacity, and the electronic transport coefficients (electrical conductivity, thermal conductivity, and thermal power). The thermodynamic values have been calculated by means of the chemical model, which also allows one to obtain the ionic composition of considered plasma. The composition has been used to calculate the electronic transport coefficients within the relaxation time approximation. The results of the present investigation have been compared with the calculations of other researchers and available data of measurements. © 2015 AIP Publishing LLC.

Eremin A.V.,RAS Joint Institute for High Temperatures
Progress in Energy and Combustion Science | Year: 2012

This review deals with the most recent achievements in experimental investigations of the process of carbon nanoparticle formation, at pyrolysis of various carbon bearing species behind shock waves. The diverse diagnostic methods of these processes are described; special attention is given to new methods for measuring the current sizes and optical properties of particles and the temperature of the reacting mixture using time resolved laser-induced incandescence (LII), and IR emission-absorption spectroscopy. The main part of the review provides critical analysis of the numerous results of the kinetics of particle formation at various temperatures, pressures and concentrations of carbon. Particular emphasis is placed on the results obtained by pyrolysis of hydrogen free precursors. It is shown that recent measurements of size dependence of the optical properties of particles, actual temperature of the mixture during pyrolysis of initial substances, and the subsequent growth of nanoparticles require a serious revision of current conceptions regarding the temperature dependence of particle yield and growth rate. Based on this analysis, unified regularities in these processes, with various temperatures and types of initial substances, are suggested. The last section of the paper contains a short review of the methods for modeling the processes of carbon nanoparticle formation in shock waves. Emphasis is placed on the necessity for the elaboration of more general models describing the detailed changes in particle properties during the growth process and the unified regularities of particle growth from hydrocarbons and hydrogen-free precursors as determined in experiments. © 2011 Elsevier Ltd. All rights reserved.

Naidis G.V.,RAS Joint Institute for High Temperatures
Plasma Sources Science and Technology | Year: 2013

Results of the modelling of OH production in the plasma bullet mode of cold atmospheric-pressure He-H2O plasma jets are presented. It is shown that the dominant source of OH molecules is related to the Penning and charge transfer reactions of H2O molecules with excited and charged helium species produced by guided streamers (plasma bullets), in contrast to the case of He-H2O glow discharges where OH production is mainly due to the dissociation of H2O molecules by electron impact. © 2013 IOP Publishing Ltd.

Naidis G.V.,RAS Joint Institute for High Temperatures
Applied Physics Letters | Year: 2011

Results of modeling of streamer propagation along helium jets for both positive and negative polarities of applied voltage are presented. Obtained patterns of streamer dynamics and structure in these two cases are similar to those observed in experiments with plasma jets. © 2011 American Institute of Physics.

Zhukhovitskii D.I.,RAS Joint Institute for High Temperatures
Physical Review E - Statistical, Nonlinear, and Soft Matter Physics | Year: 2015

Dust acoustic waves in the bulk of a dust cloud in complex plasma of low-pressure gas discharge under microgravity conditions are considered. The complex plasma is assumed to conform to the ionization equation of state (IEOS) developed in our previous study. This equation implies the ionization similarity of plasmas. We find singular points of IEOS that determine the behavior of the sound velocity in different regions of the cloud. The fluid approach is utilized to deduce the wave equation that includes the neutral drag term. It is shown that the sound velocity is fully defined by the particle compressibility, which is calculated on the basis of the used IEOS. The sound velocities and damping rates calculated for different three-dimensional complex plasmas both in ac and dc discharges demonstrate a good correlation with experimental data that are within the limits of validity of the theory. The theory provides interpretation for the observed independence of the sound velocity on the coordinate and for a weak dependence on the particle diameter and gas pressure. Predictive estimates are made for the ongoing PK-4 experiment. © 2015 American Physical Society.

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