Download or read book Shock Wave Dynamics in Weakly Ionized Plasmas written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-15 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt: An investigation of the dynamics of shock waves in weakly ionized argon plasmas has been performed using a pressure ruptured shock tube. The velocity of the shock is observed to increase when the shock traverses the plasma. The observed increases cannot be accounted for by thermal effects alone. Possible mechanisms that could explain the anomalous behavior include a vibrational/translational relaxation in the nonequilibrium plasma, electron diffusion across the shock front resulting from high electron mobility, and the propagation of ion-acoustic waves generated at the shock front. Using a turbulence model based on reduced kinetic theory, analysis of the observed results suggest a role for turbulence in anomalous shock dynamics in weakly ionized media and plasma-induced hypersonic drag reduction. Johnson, Joseph A., III Langley Research Center

Download or read book Shock Wave Dynamics in Weakly Ionized Gases written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-12-28 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: We have begun a comprehensive series of analyses and experiments to study the basic problem of shock wave dynamics in ionized media. Our objective is to isolate the mechanisms that are responsible for the decrease in the shock amplitude and also to determine the relevant plasma parameters that will be required for a drag reduction scheme in an actual high altitude hypersonic flight. Specifically, we have initiated a program of analyses and measurements with the objective of (i) fully characterizing the propagation dynamics in plasmas formed in gases of aerodynamic interest, (ii) isolating the mechanisms responsible for the decreased shock strength and increased shock velocity, (iii) extrapolating the laboratory observations to the technology of supersonic flight. Johnson, Joseph A., III Langley Research Center NAG1-1930...

Download or read book Shock Wave Propagation in Weakly Ionized Plasmas written by Igor V. Adamovich and published by . This book was released on 1997 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shock Wave Structure in a Fully Ionized Gas Based on Multi component Fluid Theory written by Huon Li and published by . This book was released on 1961 with total page 132 pages. Available in PDF, EPUB and Kindle. Book excerpt: The multi-component continuous approach for the investigation of the gasdynamics of a plasma is presented. More information about the flow properties of a plasma can be obtained than from the classical magnetohydrodynamic approach. Also, the resulting equations appear to be more easily solved than the Blotzmann equation of classical kinetic theory. The basic macroscopic conservation equations for a non-reacting multi-component plasma are presented. The fluid properties of each component are referred to the mean velocity of that component. Therefore, no limitations are placed on the magnitude of the diffusion velocities. The effects of electric and magnetic fields are included. The equations for a two-component mixture are used to study the structure of a shock wave in a fully-ionized hydrogen gas. It is assumed that the momentum exchange and energy exchange between the ions and electrons are important because of the strong Coulomb forces present. (Author).

Download or read book Studies of Anomalous Shock Wave Propagation and Dispersion in Weakly Ionized Plasma written by and published by . This book was released on 2001 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The effects of weak ionization on the strength of shock waves in supersonic gas flows were studied in an experimental program. Claims that weak ionization can substantially reduce shock wave strength, independently of any plasma heating effects, were evaluated. Experiments were conducted in both shock tubes and in supersonic, steady flow, plasma wind- tunnels. Temperatures and ionization levels in the flows were measured. It was demonstrated that shocks can be weakened by creating an electric discharge in the flow, but this effect is purely a consequence of the Joule heating of the plasma. Without heating, ionization alone does not weaken the shock.

Download or read book Physics of Collisionless Shocks written by André Balogh and published by Springer Science & Business Media. This book was released on 2013-01-04 with total page 503 pages. Available in PDF, EPUB and Kindle. Book excerpt: The present book provides a contemporary systematic treatment of shock waves in high-temperature collisionless plasmas as are encountered in near Earth space and in Astrophysics. It consists of two parts. Part I develops the complete theory of shocks in dilute hot plasmas under the assumption of absence of collisions among the charged particles when the interaction is mediated solely by the self-consistent electromagnetic fields. Such shocks are naturally magnetised implying that the magnetic field plays an important role in their evolution and dynamics. This part treats subcritical shocks which dissipate flow energy by generating anomalous resistance or viscosity. The main emphasis is, however, on super-critical shocks where the anomalous dissipation is insufficient to retard the upstream flow. These shocks, depending on the direction of the upstream magnetic field, are distinguished as quasi-perpendicular and quasi-parallel shocks which exhibit different behaviours, reflecting particles back upstream and generating high electromagnetic wave intensities. Particle acceleration and turbulence at such shocks become possible and important. Part II treats planetary bow shocks and the famous Heliospheric Termination shock as examples of two applications of the theory developed in part I.

Download or read book Physics of Shock Waves in Gases and Plasmas written by Michael A. Liberman and published by Springer. This book was released on 1986 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shock Waves in Nonequilibrium Gases and Plasmas written by William M. Hilbun and published by . This book was released on 1997-10-01 with total page 274 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis and assessment of three mechanisms describing plasma/ shock wave interactions was conducted under conditions typically encountered in a weakly ionized glow discharge. The mechanisms of ion-acoustic wave damping, post-shock energy addition and thermal inhomogeneities were examined by numerically solving the Euler equations with appropriate source terms adapted for each mechanism. Ion-acoustic wave damping was examined by modeling the partially ionized plasma as two fluids in one spatial dimension using the Riemann problem as a basis. Post-shock energy addition in the form of nonequilibrium vibrational energy relaxation was also examined in one spatial dimension using the Riemann problem as a basis. The influence of thermal inhomogeneities on shock wave propagation was examined in two spatial dimensions for both a Riemann shock and a shock generated by a spark discharge. Shocks were propagated through realistic thermal profiles with the resulting shock structure examined through the numerical application of various optical diagnostic techniques. Results from shock simulations indicate that ion-acoustic wave damping has an insignificant effect on the neutral flow at fractional ionization levels typical of glow discharges. Post-shock vibrational energy relaxation is also unable to effect the shock structure on the time scales of interest. An analysis of the effects of thermal inhomogeneities reveals that many of the observed plasma/shock anomalies can be explained based solely on this mechanism.

Download or read book Physics of Shock Waves in Gases and Plasmas written by Michael A. Libermann and published by Springer. This book was released on 1986 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As Emile Jouguet remarked, "the shock wave flew off the tip of the pen of a theoretician for the first time" about a hundred years ago. The physics of shock waves has since grown into an independent branch of science closely linked with a wide range of research areas, from astrophysics and plasma physics to solid-state physics. Since the beginning, theoretical investiga tion has kept its leading role. The present book is devoted to actual problems of the theory of shock waves in gases and plasmas, that are of general interest to physicists. It con tains the results of studies on shock structure, stability, evolutionarity and dynamics. Of special interest is the theory of shock phenomena in mag netic fields, which is important for applied research on controlled nuclear fusion. A substantial contribution to this theory has been made by these authors. This monograph is the first attempt in the literature to make a systematic presentation of the shock-structure theory.The theory is consistently sub stantiated by relevant experimental results obtained recently with the use of high-power electromagnetic shock tubes. The material contained here is applicable to the solution of a wide variety of problems arising in plasma physics, nuclear fusion and cosmic gasdynamics. I believe that this book will be of help and interest for a broad circle of research workers (physi cists, astrophysicists and engineers concerned with energy accumulation, shock phenomena and other related problems of plasma hydrodynamics) as well as for university staff, post- and undergraduates.

Download or read book Shock Waves in Collisionless Plasmas written by Derek A. Tidman and published by John Wiley & Sons. This book was released on 1971 with total page 200 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Shock Wave Structure for a Fully Ionized Plasma written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: We study the structure of planar shock waves in a two-temperature model of a fully ionized plasma that includes electron heat conduction and energy exchange between electrons and ions. For steady flow in a reference frame moving with the shock, the model reduces to an autonomous system of ordinary differential equations which can be numerically integrated. A phase space analysis of the ODEs provides additional insight into the structure of the solutions. For example, below a threshold mach number the model produces fully dispersed shocks; while above another threshold mach number, the solutions contain embedded hydrodynamic shocks. Between these two threshold values, the appearance of embedded shocks depends on the electron diffusivity and the electron-ion coupling term. We also find that the ion temperature may continue to increase after the shock and reaches a maximum near the isothermal sonic point. We summarize the methodology for solving for two-temperature shocks, and show results for several values of shock strength and material parameters to quantify the shock structure and explore the range of possible solutions. Such solutions may be used to verify hydrodynamic codes that use similar plasma physics models.

Download or read book Non Ideal Gas Effects on Shock Waves in Weakly Ionized Gases written by Robert Rubinstein and published by . This book was released on 2000 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt: A shock wave in a weakly ionized gas can be preceeded by a charge separation region if the Debye length is larger than the shock width. It has been proposed that electrostatic contributions to pressure in the charge separation region can increase the sound speed ahead of the shock well above the sound speed in a neutral gas at the same temperature and therefore increase the shock propagation speed. This proposal is investigated numerically and theoretically. It is concluded that although the ion gas becomes strongly non-ideal in the charge separation region, there is no appreciable effect on the neutral shock.

Download or read book Shock Wave Structure in Gas Mixtures and Plasmas written by S. R. M. (Stanley Ray Macniven) Sinclair and published by National Library of Canada. This book was released on 1968 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: The research was concerned with a theoretical description of shock wave structure in gaseous mixtures when diffusive effects are important. The problem considered in detail is the structure of a shock wave in a helium-argon mixture in which the argon is present in very small concentration. An anomalous result, cited in the literature, suggesting that the argon undergoes an initial pre-expansion before compression, was analysed to show the theoretical origin of this effect. The velocity distribution of a trace of heavy gas (and its lower moments) are watched as the heavy particles pass through a Mott-Smith background shock of lighter particles. The Mott-Smith background is chosen because its bimodal Maxwellian form provides an analytical determination of the free path to the next event for the heavy test particle at any point along its trajectory. This so-called Monte Carlo solution to the idealized diffusion shock problem can be used as a standard for evaluating the diffusion equations derived from various kinetic theory approximations. A number of systems of moment equations of the heavy particle Boltzmann equation were solved and the resulting heavy particle moment profiles compared with those of the Monte Carlo solution. A second strong diffusion problem was analysed from a kinetic theory point of view. It was found experimentally that the ion density profile through a shock in a weakly ionized plasma with elevated electron temperature is much more diffuse than the neutral atom shock. The theoretical analysis shows that this strong diffusion effect can be attributed to the electrical coupling between the ions and the hotter electron gas. (Author).

Download or read book Handbook of Shock Waves Three Volume Set written by Gabi Ben-Dor and published by Elsevier. This book was released on 2000-10-18 with total page 2188 pages. Available in PDF, EPUB and Kindle. Book excerpt: The Handbook of Shock Waves contains a comprehensive, structured coverage of research topics related to shock wave phenomena including shock waves in gases, liquids, solids, and space. Shock waves represent an extremely important physical phenomena which appears to be of special practical importance in three major fields: compressible flow (aerodynamics), materials science, and astrophysics. Shock waves comprise a phenomenon that occurs when pressure builds to force a reaction, i.e. sonic boom that occurs when a jet breaks the speed of sound.This Handbook contains experimental, theoretical, and numerical results which never before appeared under one cover; the first handbook of its kind.The Handbook of Shock Waves is intended for researchers and engineers active in shock wave related fields. Additionally, R&D establishments, applied science & research laboratories and scientific and engineering libraries both in universities and government institutions. As well as, undergraduate and graduate students in fluid mechanics, gas dynamics, and physics. Key Features* Ben-Dor is known as one of the founders of the field of shock waves* Covers a broad spectrum of shock wave research topics* Provides a comprehensive description of various shock wave related subjects* First handbook ever to include under one separate cover: experimental, theoretical, and numerical results

Download or read book EXPERIMENTAL STUDY OF SHOCK WAVE DYNAMICS IN MAGNETIZED PLASMAS written by and published by . This book was released on 2009 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this four-year project (including one-year extension), the project director and his research team built a shock-wave-plasma apparatus to study shock wave dynamics in glow discharge plasmas in nitrogen and argon at medium pressure (1-20 Torr), carried out various plasma and shock diagnostics and measurements that lead to increased understanding of the shock wave acceleration phenomena in plasmas. The measurements clearly show that in the steady-state dc glow discharge plasma, at fixed gas pressure the shock wave velocity increases, its amplitude decreases, and the shock wave disperses non-linearly as a function of the plasma current. In the pulsed discharge plasma, at fixed gas pressure the shock wave dispersion width and velocity increase as a function of the delay between the switch-on of the plasma and shock-launch. In the afterglow plasma, at fixed gas pressure the shock wave dispersion width and velocity decrease as a function of the delay between the plasma switch-off and shock-launch. These changes are found to be opposite and reversing towards the room temperature value which is the initial condition for plasma ignition case. The observed shock wave properties in both igniting and afterglow plasmas correlate well with the inferred temperature changes in the two plasmas.

Download or read book Double Layer Effects on Shock Wave Propagation written by Shannon Walker and published by . This book was released on 1999-03-01 with total page 102 pages. Available in PDF, EPUB and Kindle. Book excerpt: An analysis and assessment of two mechanisms in plasma shock interactions was conducted under conditions typically encountered in a weakly ionized glow discharge. The mechanisms of a spatially-dependent electron temperature and additional electron impact ionization at the shock front were examined for effects on shock structure and propagation. These mechanisms were incorporated into an existing one-dimensional, time-dependent, fluid dynamics code that uses the Riemami problem as a basis and numerically solves the Euler equations for two fluids: the neutral gas and the charged component. The spatial variation in electron temperature was modeled as a shock-centered rise in temperature. Additional ionization was modeled by incorporating a variable electron temperature and a quasi-kinetic collision function, for both unrestricted ionization and ionization mitigated by ion-electron recombination. Introduction of a spatial variation in electron temperature resulted in a broadening and strengthening of the electric field associated with the electronic double layer (EDL) at the shock front. Results of unrestricted ionization were a broadening and strengthening of the electric field associated with the EDL, acceleration of the neutral shock front, and the development of a neutral precursor ahead of the shock. Ion-electron recombination was seen to reduce these effects.

Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.