Study on Magnetohydrodynamic Turbulence and Its Astrophysical Applications

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.

Study on Magnetohydrodynamic Turbulence and Its Astrophysical Applications

Author: Siyao Xu

Publisher: Springer

ISBN: 9811375151

Page: 157

View: 853

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.

Broken Symmetry in Ideal Magnetohydrodynamic Turbulence

Broken Symmetry in Ideal Magnetohydrodynamic Turbulence

Author: John V. Shebalin

Publisher:

ISBN:

Page: 17

View: 414

A numerical study of the long-time evolution of a number of cases of inviscid, isotropic, incompressible, three-dimensional fluid and magneto-fluid turbulence has been completed. The results confirm that ideal magnetohydrodynamic turbulence is non-ergodic if there is no external magnetic field present. This is due essentially to a canonical symmetry being broken in an arbitrary dynamical representation. The broken symmetry manifests itself as a coherent structure, i.e., a non-zero time-averaged part of the turbulent magnetic field. The coherent structure is observed, in one case, to contain about eighteen percent of the total energy. Isotropic turbulence, Ideal magnetohydrodynamics, Broken symmetry.

Magnetohydrodynamic Turbulence

... I. D. and Townsend, A. (1959). Small-scale variation of convected quantities
like temperature in a turbulent fluid. ... Dynamics and statistics in inverse cascade
processes in 2D magnetohydrodynamic turbulence, Phys. Rev. Lett. 72, 3469–72
.

Magnetohydrodynamic Turbulence

Author: Dieter Biskamp

Publisher: Cambridge University Press

ISBN: 9781139441674

Page:

View: 316

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.

MHD Turbulence

Consequences of and Techniques for Studies Huirong Yan. Chapter 2 Cosmic
ray Transport in a Compressible Magnetohydrodynamic Turbulence Abstract
Recent advances in understanding of magnetohydrodynamic ( MHD ) 5.

MHD Turbulence

Author: Huirong Yan

Publisher:

ISBN:

Page: 146

View: 295

Turbulence in Magnetohydrodynamics

[78] J. Cho, Simulations of relativistic force-free magnetohydrodynamic
turbulence, Astrophys.J. 621 (2005), 324–327. [79] J. Cho, Non-locality of
hydrodynamic and magnetohydrodynamic turbulence, Astrophys. J. 725 (2010),
1786–1791.

Turbulence in Magnetohydrodynamics

Author: Andrey Beresnyak

Publisher: Walter de Gruyter GmbH & Co KG

ISBN: 3110263289

Page: 286

View: 457

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.

Large Eddy Simulations of Compressible Magnetohydrodynamic Turbulence

Supersonic, magnetohydrodynamic (MHD) turbulence is thought to play an important role in many processes - especially in astrophysics, where detailed three-dimensional observations are scarce.

Large Eddy Simulations of Compressible Magnetohydrodynamic Turbulence

Author: Philipp Grete

Publisher:

ISBN:

Page:

View: 972

Supersonic, magnetohydrodynamic (MHD) turbulence is thought to play an important role in many processes - especially in astrophysics, where detailed three-dimensional observations are scarce. Simulations can partially fill this gap and help to understand these processes. However, direct simulations with realistic parameters are often not feasible. Consequently, large eddy simulations (LES) have emerged as a viable alternative. In LES the overall complexity is reduced by simulating only large and intermediate scales directly. The smallest scales, usually referred to as subgrid-scales (SGS), ...

Broken Symmetry in Ideal Magnetohydrodynamic Turbulence

The results confirm that ideal magnetohydrodynamic turbulence is non-ergodic if there is no external magnetic field present. This is due essentially to a canonical symmetry being broken in an arbitrary dynamical representation.

Broken Symmetry in Ideal Magnetohydrodynamic Turbulence

Author: National Aeronautics and Space Administration (NASA)

Publisher: Createspace Independent Publishing Platform

ISBN: 9781725194755

Page: 38

View: 489

A numerical study of the long-time evolution of a number of cases of inviscid, isotropic, incompressible, three-dimensional fluid, and magneto-fluid turbulence has been completed. The results confirm that ideal magnetohydrodynamic turbulence is non-ergodic if there is no external magnetic field present. This is due essentially to a canonical symmetry being broken in an arbitrary dynamical representation. The broken symmetry manifests itself as a coherent structure, i.e., a non-zero time-averaged part of the turbulent magnetic field. The coherent structure is observed, in one case, to contain about eighteen percent of the total energy. Shebalin, John V. Unspecified Center NASA-TM-109017, ICASE-93-49, NAS 1.15:109017, AD-A272673 RTOP 505-90-52-01...

Turbulence and Nonlinear Dynamics in MHD Flows

Turbulence and Nonlinear Dynamics in MHD Flows M. Meneguzzi, A. Pquuet
and PL. Sulem (Editors) © Elsevier Science Publishers B.V. (North-Holland),
1989 ON THE ORIGIN OF SOLAR WIND TURBULENCE: HELIOS DATA
REVISITED ...

Turbulence and Nonlinear Dynamics in MHD Flows

Author: M. Meneguzzi

Publisher: Elsevier

ISBN: 0444598731

Page: 290

View: 234

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.

Nonlinear MHD Waves and Turbulence

Recent developments in the derivation of reduced models for weakly
compressible magnetohydrodynamic (MHD) turbulence are discussed. A four-
field system of equations has been derived from the compressible
magnetohydrodynamic ...

Nonlinear MHD Waves and Turbulence

Author: Thierry Passot

Publisher: Springer Science & Business Media

ISBN: 3540666974

Page: 385

View: 412

The workshop "Nonhnear MHD Waves and Turbulence" was held at the - servatoire de Nice, December 1-4, 1998 and brought together an international group of experts in plasma physics, fluid dynamics and applied mathematics. The aim of the meeting was to survey the current knowledge on two main topics: (i) propagation of plasma waves (like Alfven, whistler or ion-acoustic waves), their instabilities and the development of a nonlinear dynamics lea ding to solitonic structures, wave collapse or weak turbulence; (ii) turbulence in magnetohydrodynamic flows and its reduced description in the presence of a strong ambient magnetic fleld. As is well known, both aspects play an important role in various geophysical or astrophysical media such as the - gnetospheres of planets, the heliosphere, the solar wind, the solar corona, the interplanetary and interstellar media, etc. This volume, which includes expanded versions of oral contributions pre sented at this meeting, should be of interest for a large community of resear chers in space plasmas and nonlinear sciences. Special effort was made to put the new results into perspective and to provide a detailed literature review. A main motivation was the attempt to relate more closely the theoretical un derstanding of MHD waves and turbulence (both weak and strong) with the most recent observations in space plasmas. Some papers also bring interesting new insights into the evolution of hydrodynamic or magnetohydrodynamic structures, based on systematic asymptotic methods.

Nonlinear Processes in Geophysics

Three key issues are identified regarding the use of Hall MHD to describe
turbulence in kinetic plasmas : ( 1 ) what are the wave modes comprising the
turbulence at scales kd ; > 1 ?; ( 2 ) are the collisionless damping rates from
linear kinetic ...

Nonlinear Processes in Geophysics

Author:

Publisher:

ISBN:

Page:

View: 472

Advances in Turbulence 7

Shebalin , J . V . , Matthaeus , W . H . & Montgomery , D . ( 1983 ) Anisotropy in
MHD turbulence due to a mean magnetic ... of shear - Alfvén wave packets :
Implications for weak magnetohydrodynamic turbulence in astrophysical plasmas
.

Advances in Turbulence 7

Author: Uriel Frisch

Publisher: Springer Science & Business Media

ISBN:

Page: 613

View: 456

This volume contains an overview of the state of turbulence research with some bias towards work done in Europe. It represents an almost complete collection of the invited and contributed papers delivered at the Seventh European Turbulence Conference, sponsored by EUROMECH and ERCOFTAC and organized by the Observatoire de la Cote d'Azur. High-Reynolds number experiments combined with techniques of imaging, non-intrusive probing, processing and simulation provide high-quality data which put significant constraints on possible theories. For the first time, it has been shown, for a class of passive scalar problems, why dimensional analysis sometimes gives the wrong answers and how anomalous intermittency corrections can be calculated from first principles. The volume is thus geared towards specialists in the area of flow turbulence who could not attend the conference as well as anybody interested in this rapidly-moving field.

Magnetic Helicity in Space and Laboratory Plasmas

Montgomery, D., L. Turner, and G. Vahala, Three dimensional
magnetohydrodynamic turbulence in cylindrical geometry, Phys. Fluids 21, 757-
764, 1978. Montgomery, D., and L. Phillips, Minimum dissipation rates in
magnetohydrodynamics, ...

Magnetic Helicity in Space and Laboratory Plasmas

Author: Michael R. Brown

Publisher: American Geophysical Union

ISBN:

Page: 304

View: 914

Published by the American Geophysical Union as part of the Geophysical Monograph Series, Volume 111. Using the concept of magnetic helicity, physicists and mathematicians describe the topology of magnetic fields: twisting, writhing, and linkage. Mathematically, helicity is related to linking integrals, which Gauss introduced in the 19th century to describe the paths of asteroids in the sky. In the late 1970s the concept proved to be critical to understand laboratory plasma experiments on magnetic reconnection, dynamos, and magnetic field relaxation. In the late 1980s it proved equally important in understanding turbulence in the solar wind and the interplanetary magnetic field. During the last five years interest in magnetic helicity has grown dramatically in solar physics, and it will continue to grow as observations of vector magnetic fields become increasingly sophisticated.

Magnetohydrodynamics

The conflicting results achieved using different expansion methods led us to a
speculative deduction that the double expansion applied here is physically close
to the description of quasi - two - dimensional ( 2 < d < 3 ) turbulent flows .

Magnetohydrodynamics

Author:

Publisher:

ISBN:

Page:

View: 460

International Aerospace Abstracts

... developed magnetohydrodynamic turbulence ( c75 A95 - 16545 ) Convective -
type instabilities in developed small - scale magnetohydrodynamic turbulence (
c75 A95 - 16549 ) Modified adiabatic approximation for a hydrogen atom moving
 ...

International Aerospace Abstracts

Author:

Publisher:

ISBN:

Page:

View: 341

Turbulence and Nonlinear Processes in Astrophysical Plasmas

G . S . Patterson and S . A . Orszag , Spectral calculation of isotropic turbulence :
Efficient removal of aliasing interaction , Phys . Fluids , 14 ( 1971 ) , 2538 – 2541 .
9 . J . V . Shebalin , Anisotropy in MHD turbulence due to a mean magnetic field ...

Turbulence and Nonlinear Processes in Astrophysical Plasmas

Author: International IGPP Conference

Publisher: Amer Inst of Physics

ISBN:

Page: 434

View: 519

This book contains the peer-reviewed papers presented at the Sixth Annual International Astrophysics Conference. This conference brought together a range of topics that shed light on our understanding and status of turbulence and nonlinear processes in astrophysical plasmas. Coverage in this volume includes turbulent relaxation in laboratory and space plasmas and its application to coronal flux tubes, coronal heating, and the diffusion of energetic particles.

Lecture Notes on Turbulence

MAGNETOHYDRODYNAMIC TURBULENCE Preface Magnetohydrodynamic (
MHD ) turbulence is more difficult to present in lectures than fluid turbulence is ,
for several reasons : ( 1 ) less is known about it , theoretically and experimentally
 ...

Lecture Notes on Turbulence

Author: Jackson R. Herring

Publisher: World Scientific

ISBN: 9789971508272

Page: 371

View: 546

This book is a formal presentation of lectures given at the 1987 Summer School on Turbulence, held at the National Center for Atmospheric Research under the auspices of the Geophysical Turbulence Program. The lectures present in detail certain of the more challenging and interesting current turbulence research problems in engineering, meteorology, plasma physics, and mathematics. The lecturers-Uriel Frisch (Mathematics), Douglas Lilly (Meteorology), David Montgomery (Plasma Physics), and Hendrik Tennekes (Engineering) ? are distinguished for both their research contributions and their abilities to communicate these to students with enthusiasm. This book is distinguished by its simultaneous focus on the fundamentals of turbulent flows (in neutral and ionized fluids) and on a presentation of current research tools and topics in these fields.

Proceedings of the Mini workshop on Physical Processes in the Solar Transition region and Corona Institute of Theoretical Astrophysics University of Oslo 18 20 June 1990

Marsch , E. , MHD Turbulence in the Solar Wind , in Physics of the Inner
Heliosphere , Vol . II , ed . by R. Schwenn and E. Marsch , Springer - Verlag ,
Heidelberg , in press , 1990a . Marsch , E. , Kinetic physics of the solar wind
plasma , in ...

Proceedings of the Mini workshop on Physical Processes in the Solar Transition region and Corona  Institute of Theoretical Astrophysics  University of Oslo  18 20 June 1990

Author: P. Maltby

Publisher:

ISBN:

Page: 199

View: 410