Download or read book Study on Magnetohydrodynamic Turbulence and Its Astrophysical Applications written by Siyao Xu and published by Springer. This book was released on 2019-04-23 with total page 157 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulence and magnetic fields are ubiquitous in the Universe. Their importance to astronomy cannot be overestimated. The theoretical advancements in magnetohydrodynamic (MHD) turbulence achieved during the past two decades have significantly influenced many fields of astronomy. This book provides predictive theories of the magnetic field generation by turbulence and the dissipation of MHD turbulence. These fundamental non-linear problems were believed to be tractable only numerically. This book provides complete analytical descriptions in quantitative agreement with existing numerics, as well as theoretical predictions in physical regimes still unreachable by simulations, and explanations of various related observations. It also discusses and promotes the astrophysical applications of MHD turbulence theories, including (i) the particle acceleration and radiation in high-energy phenomena, e.g., Gamma-Ray Bursts, supernova remnants, cosmic rays; (ii) interstellar density fluctuations and the effect on observations, e.g., Faraday rotation, scattering measurements of Galactic and extragalactic radio sources; (iii) density and magnetic field structure in molecular clouds toward star formation. In closing, this book demonstrates the key role of MHD turbulence in connecting diverse astrophysical processes and unraveling long-standing astrophysical problems, as foreseen by Chandrasekhar, a founder of modern astrophysics.
Download or read book Magnetohydrodynamic Turbulence written by Dieter Biskamp and published by Cambridge University Press. This book was released on 2003-07-31 with total page 313 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an introduction to, and modern account of, magnetohydrodynamic (MHD) turbulence, an active field both in general turbulence theory and in various areas of astrophysics. The book starts by introducing the MHD equations, certain useful approximations and the transition to turbulence. The second part of the book covers incompressible MHD turbulence, the macroscopic aspects connected with the different self-organization processes, the phenomenology of the turbulence spectra, two-point closure theory, and intermittency. The third considers two-dimensional turbulence and compressible (in particular, supersonic) turbulence. Because of the similarities in the theoretical approach, these chapters start with a brief account of the corresponding methods developed in hydrodynamic turbulence. The final part of the book is devoted to astrophysical applications: turbulence in the solar wind, in accretion disks, and in the interstellar medium. This book is suitable for graduate students and researchers working in turbulence theory, plasma physics and astrophysics.
Download or read book Turbulence in Magnetohydrodynamics written by Andrey Beresnyak and published by Walter de Gruyter GmbH & Co KG. This book was released on 2019-07-08 with total page 434 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetohydrodynamics describes dynamics in electrically conductive fluids. These occur in our environment as well as in our atmosphere and magnetosphere, and play a role in the sun's interaction with our planet. In most cases these phenomena involve turbulences, and thus are very challenging to understand and calculate. A sound knowledge is needed to tackle these problems. This work gives the basic information on turbulence in nature, comtaining the needed equations, notions and numerical simulations. The current state of our knowledge and future implications of MHD turbulence are outlined systematically. It is indispensable for all scientists engaged in research of our atmosphere and in space science.
Download or read book Magnetohydrodynamic Turbulence written by D. Biskamp and published by . This book was released on 2003 with total page 297 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book presents an introduction to, and state-of-the-art account of, magnetohydrodynamic (MHD) turbulence. Applications to three topics from astrophysics are considered: the solar wind, accretion disks, and the interstellar medium. Suitable for graduate students and researchers working in turbulence theory, plasma physics and astrophysics.
Download or read book Mhd Turbulence written by Huirong Yan and published by LAP Lambert Academic Publishing. This book was released on 2012-05 with total page 264 pages. Available in PDF, EPUB and Kindle. Book excerpt: The last decade has been marked by substantial advamces in understanding of the role and properties of astrophysical turbulent magnetic fields. This has induced substancial paradigm shifts for the problem of cosmic ray propagation and acceleration. This book introduces to the reader the mordern understanding of magnetohydrodynamic (MHD) turbulence and describes how the advances in MHD turbulence theory affect the key aspects of particle acceleration and transport in astrophysical environments. The book presents the implications of the improved treatment of cosmic ray dynamics for various problems ranging from particle acceleration in solar flares and the propagation of cosmic rays in the galaxy to powering enigmatic gamma ray bursts. In addition, the book discusses the acceleration of dust grains by MHD turbulence as well as new ways of observational studies of magnetic fields based on ground state alignment. The book should be useful for astrophysics graduate students and anyone interested at the current developments in MHD turbulence theory and its astrophysical implications.
Download or read book Magnetohydrodynamics written by Sergei S. Molokov and published by Springer Science & Business Media. This book was released on 2007-08-26 with total page 408 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book revises the evolution of ideas in various branches of magnetohydrodynamics (astrophysics, earth and solar dynamos, pinch, MHD turbulence and liquid metals) and reviews current trends and challenges. Uniquely, it contains the review articles on the development of the subject by pioneers in the field as well as leading experts, not just in one, but in various branches of magnetohydrodynamics, such as liquid metals, astrophysics, dynamo and pinch.
Download or read book Introduction to Modern Magnetohydrodynamics written by Sébastien Galtier and published by Cambridge University Press. This book was released on 2016-10-06 with total page 285 pages. Available in PDF, EPUB and Kindle. Book excerpt: Ninety-nine percent of ordinary matter in the Universe is in the form of ionized fluids, or plasmas. The study of the magnetic properties of such electrically conducting fluids, magnetohydrodynamics (MHD), has become a central theory in astrophysics, as well as in areas such as engineering and geophysics. This textbook offers a comprehensive introduction to MHD and its recent applications, in nature and in laboratory plasmas; from the machinery of the Sun and galaxies, to the cooling of nuclear reactors and the geodynamo. It exposes advanced undergraduate and graduate students to both classical and modern concepts, making them aware of current research and the ever-widening scope of MHD. Rigorous derivations within the text, supplemented by over 100 illustrations and followed by exercises and worked solutions at the end of each chapter, provide an engaging and practical introduction to the subject and an accessible route into this wide-ranging field.
Download or read book Phenomenology Treatment of Magnetohydrodynamic Turbulence with Non equipartition and Anisotropy written by and published by . This book was released on 2005 with total page 8 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetohydrodynamics (MHD) turbulence theory, often employed satisfactorily in astrophysical applications, has often focused on parameter ranges that imply nearly equal values of kinetic and magnetic energies and length scales. However, MHD flow may have disparity magnetic Prandtl number, dissimilar kinetic and magnetic Reynolds number, different kinetic and magnetic outer length scales, and strong anisotropy. Here a phenomenology for such ''non-equipartitioned'' MHD flow is discussed. Two conditions are proposed for a MHD flow to transition to strong turbulent flow, extensions of (1) Taylor's constant flux in an inertial range, and (2) Kolmogorov's scale separation between the large and small scale boundaries of an inertial range. For this analysis, the detailed information on turbulence structure is not needed. These two conditions for MHD transition are expected to provide consistent predictions and should be applicable to anisotropic MHD flows, after the length scales are replaced by their corresponding perpendicular components. Second, it is stressed that the dynamics and anisotropy of MHD fluctuations is controlled by the relative strength between the straining effects between eddies of similar size and the sweeping action by the large-eddies, or propagation effect of the large-scale magnetic fields, on the small scales, and analysis of this balance in principle also requires consideration of non-equipartition effects.
Download or read book Cosmic Ray Astrophysics written by Reinhard Schlickeiser and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 521 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the first part, the book gives an up-to-date summary of the observational data. In the second part, it deals with the kinetic description of cosmic ray plasma. The underlying diffusion-convection transport equation, which governs the coupling between cosmic rays and the background plasma, is derived and analyzed in detail. In the third part, several applications of the solutions of the transport equation are presented and how key observations in cosmic ray physics can be accounted for is demonstrated.
Download or read book Research in Magnetohydrodynamics and Its Astrophysical Applications written by Max Krook and published by . This book was released on 1963 with total page 20 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Hydrodynamic and Magnetohydrodynamic Turbulent Flows written by A. Yoshizawa and published by Springer Science & Business Media. This book was released on 2013-03-14 with total page 426 pages. Available in PDF, EPUB and Kindle. Book excerpt: TUrbulence modeling encounters mixed evaluation concerning its impor tance. In engineering flow, the Reynolds number is often very high, and the direct numerical simulation (DNS) based on the resolution of all spatial scales in a flow is beyond the capability of a computer available at present and in the foreseeable near future. The spatial scale of energetic parts of a turbulent flow is much larger than the energy dissipative counterpart, and they have large influence on the transport processes of momentum, heat, matters, etc. The primary subject of turbulence modeling is the proper es timate of these transport processes on the basis of a bold approximation to the energy-dissipation one. In the engineering community, the turbulence modeling is highly evaluated as a mathematical tool indispensable for the analysis of real-world turbulent flow. In the physics community, attention is paid to the study of small-scale components of turbulent flow linked with the energy-dissipation process, and much less interest is shown in the foregoing transport processes in real-world flow. This research tendency is closely related to the general belief that universal properties of turbulence can be found in small-scale phenomena. Such a study has really contributed much to the construction of statistical theoretical approaches to turbulence. The estrangement between the physics community and the turbulence modeling is further enhanced by the fact that the latter is founded on a weak theoretical basis, compared with the study of small-scale turbulence.
Download or read book Magnetohydrodynamics written by Sergei S. Molokov and published by Springer Verlag. This book was released on 2007-08-20 with total page 407 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetohydrodynamics (MHD) studies the interaction between the flow of an electrically conducting fluid and magnetic fields. It involves such diverse topics as the evolution and dynamics of astrophysical objects, thermonuclear fusion, metallurgy and semiconductor crystal growth, etc. Although the first ideas in magnetohydrodynamics appeared at the beginning of the last century, the "explosion" in theoretical and experimental studies occurred in the 1950s-60s. This state-of-the-art book aims at revising the evolution of ideas in various branches of magnetohydrodynamics (astrophysics, earth and solar dynamos, plasmas, MHD turbulence and liquid metals) and reviews current trends and challenges.
Download or read book Turbulence and Magnetic Fields in Astrophysics written by Edith Falgarone and published by Springer. This book was released on 2008-01-11 with total page 466 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book contains review articles of most of the topics addressed at the conf- ence on Simulations of Magnetohydrodynamic turbulence in astrophysics: recent achievements and perspectives which took place from July 2 to 6, 2001 at the Institut Henri Poincar ́e in Paris. We made the choice to publish these lectures in a tutorial form so that they can be read by a broad audience. As a result, this book does not give an exhaustive view of all the subjects addressed during the conference. The main objective of this workshop which gathered about 90 scientists from di?erent ?elds, was to present and confront recent results on the topic of t- bulence in magnetized astrophysical environments. A second objective was to discuss the latest generation of numerical codes, such as those using adaptive mesh re?nement (AMR) techniques. During a plenary discussion at the end of the workshop discussions were held on several topics, often at the heart of vivid controversies. Topics included the timescale for the dissipation of magneto-hydrodynamical (MHD) turbulence, the role of boundary conditions, the characteristics of imbalanced turbulence, the validity of the polytropic approach to Alfv ́en waves support within interst- lar clouds, the source of turbulence inside clouds devoid of stellar activity, the timescale for star formation, the Alfv ́en Mach number of interstellar gas motions, the formation process for helical ?elds in the interstellar medium. The impact of small upon large scales was also discussed.
Download or read book Lectures in Magnetohydrodynamics written by Dalton D. Schnack and published by Springer. This book was released on 2009-08-29 with total page 323 pages. Available in PDF, EPUB and Kindle. Book excerpt: Magnetohydrodynamics, or MHD, is a theoretical way of describing the statics and dynamics of electrically conducting uids. The most important of these uids occurring in both nature and the laboratory are ionized gases, called plasmas. These have the simultaneous properties of conducting electricity and being electrically charge neutral on almost all length scales. The study of these gases is called plasma physics. MHD is the poor cousin of plasma physics. It is the simplest theory of plasma dynamics. In most introductory courses, it is usually afforded a short chapter or lecture at most: Alfven ́ waves, the kink mode, and that is it. (Now, on to Landau damping!) In advanced plasma courses, such as those dealing with waves or kinetic theory, it is given an even more cursory treatment, a brief mention on the way to things more profound and interesting. (It is just MHD! Besides, real plasma phy- cists do kinetic theory!) Nonetheless, MHD is an indispensable tool in all applications of plasma physics.
Download or read book An Introduction to Magnetohydrodynamics written by P. A. Davidson and published by Cambridge University Press. This book was released on 2001-03-05 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: This book is an introductory text on magnetohydrodynamics (MHD) - the study of the interaction of magnetic fields and conducting fluids.
Download or read book Instability driven Magnetohydrodynamic Turbulence written by Justin Wiiliam Walker and published by . This book was released on 2019 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Instability-driven turbulence is ubiquitous in astrophysical and laboratory plasmas, where it is an important component to how these systems transport energy, momentum, particles, etc. This thesis is concerned with how two instabilities drive and interact with magnetohydrodynamic turbulence. The magnetorotational instability (MRI) is the best candidate for driving turbulence in well-ionized accretion disks. In this thesis, the turbulence driven by the MRI is studied with a particular focus on how it compares to strong, driven, incompressible MHD turbulence. High-resolution, high- Reynolds number setups are analyzed to determine the existence and character of an inertial range of scales where a nonlinear cascade dominates the dynamics. In contrast to previous studies, systems with an imposed magnetic field- that activate the linear MRI-provide evidence for the existence of an inertial range when one considers the dynamics perpendicular to a strong, large-scale axial magnetic field that develops in the system. The outer scale of the turbulence is determined by balance between the linear shear, present at all scales, and the turbulent shear. In the case of a system without an imposed magnetic field-where the MRI dynamo is subcritical-evidence is found for self-sustained turbulence at magnetic Prandtl number Pm = 1. Previous work was not able produce such turbulence for systems at lower Reynolds numbers. A turbulent state is found to be easier to self-sustain in these systems in high-aspect-ratio domains, with angular momentum transport also highly dependent on aspect ratio. Vertically-extended domains exhibit higher transport. Azimuthally- extended domains show increased transport until a certain aspect ratio, beyond which the transport decreases. A phenomenological explanation is proposed by which the separation of toroidal magnetic flux vertically allows for increased transport and drive of the subcritical MRI dynamo; as the toroidal dimension is extended, the tearing mode acts to break up such large scale flux, reducing transport. Additionally, two-dimensional MHD turbulence is studied in order to test the predictions of new theories that hypothesize competition between the tearing mode and turbulent fluctuations in flows with high Lundquist number. A method is introduced to simulate evolution of single, critically- balanced eddy, thereby allowing the direct investigation of this competition. Results demonstrate the disruption of the correlated eddy structure on the shorter of the [Alfven] or tearing time. Steepening of the energy spectrum is observed, while decreased alignment is not. Generally, these results support the proposed theory, with further investigation warranted.
Download or read book Turbulence and Nonlinear Dynamics in MHD Flows written by M. Meneguzzi and published by Elsevier. This book was released on 2012-12-02 with total page 290 pages. Available in PDF, EPUB and Kindle. Book excerpt: Topics discussed at this international workshop include: magnetic fields in astrophysical flows, slow and fast dynamos, MHD turbulence in space plasmas and in the laboratory, exact solutions to MHD, topology and chaos in MHD, helicity and velocity-magnetic correlations, turbulent reconnection and non-magnetic flows.
