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

Author: Dieter Biskamp

Publisher: Cambridge University Press

ISBN: 9781139441674

Category: Science

Page:

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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.

A significant progress has been achieved in the understanding of the magnetohydrodynamic (MHD) turbulence since the turn of the century, and this enables us to better describe turbulence in magnetized and partially ionized plasmas.

Author: Siyao Xu

Publisher: Springer

ISBN: 9789811375156

Category: Science

Page: 157

View: 641

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.

It may be regarded as the electric field generated by turbulence effects. In the context of the Cowling's ... '03, " or, '" 6a, with the solenoidal condition V u = V b = MAGNETOHYDRODYNAMIC TURBULENCE MODELING 323 Turbulence Equations.

Author: A. Yoshizawa

Publisher: Springer Science & Business Media

ISBN: 9789401718103

Category: Science

Page: 416

View: 656

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.

A. Beresnyak, Spectra of strong magnetohydrodynamic turbulence from high-resolution simulations, Astrophys. J. Lett. 784 (2014), L20. A. Beresnyak, On the parallel spectrum in magnetohydrodynamic turbulence, Astrophys.J. Lett.

Author: Andrey Beresnyak

Publisher: Walter de Gruyter GmbH & Co KG

ISBN: 9783110263282

Category: Science

Page: 286

View: 628

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.

Grappin, R. Frisch, U., Leorat J., Pouquet, A. (1982) Alfvén fluctuations as asymptotic states of mhd turbulence. Astron. Astrophys. 105, 6-14 7. Carbone, V., Veltri, P. (1990) A shell model for anisotropic magnetohydrodynamic ...

Author: Thierry Passot

Publisher: Springer Science & Business Media

ISBN: 9783540666974

Category: Science

Page: 385

View: 513

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.

Simulations of incompressible magnetohydrodynamic turbulence. Astrophys. J. 554: 1175–1196. Matthaeus WH, Ghosh S, Oughton S, Roberts DA. 1996. Anisotropic threedimensional MHD turbulence. J. Geophys. Res. 101: 7619–7629.

Author: Victor Shrira

Publisher: World Scientific

ISBN: 9789814520805

Category: Mathematics

Page: 296

View: 314

Wave or weak turbulence is a branch of science concerned with the evolution of random wave fields of all kinds and on all scales, from waves in galaxies to capillary waves on water surface, from waves in nonlinear optics to quantum fluids. In spite of the enormous diversity of wave fields in nature, there is a common conceptual and mathematical core which allows to describe the processes of random wave interactions within the same conceptual paradigm, and in the same language. The development of this core and its links with the applications is the essence of wave turbulence science (WT) which is an established integral part of nonlinear science.The book comprising seven reviews aims at discussing new challenges in WT and perspectives of its development. A special emphasis is made upon the links between the theory and experiment. Each of the reviews is devoted to a particular field of application (there is no overlap), or a novel approach or idea. The reviews cover a variety of applications of WT, including water waves, optical fibers, WT experiments on a metal plate and observations of astrophysical WT.

FUNDING NUMBERS BROKEN SYMMETRY IN IDEAL MAGNETOHYDRODYNAMIC TURBULENCE WU 505-90-52-01 6. AUTHOR ( S ) John V. Shebalin 8. PERFORMING ORGANIZATION REPORT NUMBER 7. PERFORMING ORGANIZATION NAME ( S ) AND ADDRESS ( ES ) Institute for ...

Author: John V. Shebalin

Publisher:

ISBN: NASA:31769000621113

Category:

Page: 17

View: 715

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.

Mason, J., Cattaneo, F. 85 Boldyrev, S. 2006 Dynamic Alignment in Driven Magnetohydrodynamic Turbulence. Physical Review Letters 97, 255002. Mason, J., Cattaneo, F. 85 Boldyrev, S. 2008 Numerical measurements of the spectrum in ...

Author: Peter A. Davidson

Publisher: Cambridge University Press

ISBN: 9780521769440

Category: Science

Page: 437

View: 427

Leading experts summarize our current understanding of the fundamental nature of turbulence, covering a wide range of topics.

From Compressible MHD to Collisionless Plasma Yan Yang. 38. 39. 40. 41. 42. 43. 44. 45. 46. 47. ... Space Sci Rev 194:97–137 Mininni PD (2011) Scale interactions in magnetohydrodynamic turbulence. Ann Rev Fluid Mech 43:377–397 Mininni ...

Author: Yan Yang

Publisher: Springer

ISBN: 9789811381492

Category: Science

Page: 134

View: 913

This book revisits the long-standing puzzle of cross-scale energy transfer and dissipation in plasma turbulence and introduces new perspectives based on both magnetohydrodynamic (MHD) and Vlasov models. The classical energy cascade scenario is key in explaining the heating of corona and solar wind. By employing a high-resolution hybrid (compact finite difference & WENO) scheme, the book studies the features of compressible MHD cascade in detail, for example, in order to approximate a real plasma cascade as “Kolmogorov-like” and to understand features that go beyond the usual simplified theories based on incompressible models. When approaching kinetic scales where plasma effects must be considered, it uses an elementary analysis of the Vlasov–Maxwell equations to help identify the channels through which energy transfer must be dissipated. In addition, it shows that the pressure–strain interaction is of great significance in producing internal energy. This analysis, in contrast to many other recent studies, does not make assumptions about wave-modes, instability or other specific mechanisms responsible for the dynamics – the results are direct consequences of the Vlasov–Maxwell system of equations. This is an important step toward understanding dissipation in turbulent collisionless plasma in space and astrophysics.

Quataert E, Gruzinov A (1999) Turbulence and particle heating in advectiondominated accretion flows. Astrophys J 520:248–255 ... Astrophys J 153:371–388 Goldstein ML, Roberts DA (1999) Magnetohydrodynamic turbulence in the solar wind.

Author: Sergei S. Molokov

Publisher: Springer Science & Business Media

ISBN: 9781402048333

Category: Science

Page: 410

View: 383

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.