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Related papers: MHD simulations of small and large scale dynamos

200 papers

On the framework of relativistic force-free magnetohydrodynamic (MHD) turbulence, we explore the fundamental properties of strong and weak turbulent cascades using high-resolution numerical simulations in the presence of a uniform…

High Energy Astrophysical Phenomena · Physics 2026-01-14 Na-Na Gao , Jian-Fu Zhang , Jungyeon Cho

Two-dimensional magnetohydrodynamics (2D MHD), forced at (a) large length scales or (b) small length scales, displays turbulent, but statistically steady, states with widely different statistical properties. We present a systematic,…

Fluid Dynamics · Physics 2019-06-27 Debarghya Banerjee , Rahul Pandit

We investigate the scaling behavior of longitudinal and transverse structure functions in homogeneous and isotropic magneto-hydrodynamic (MHD) turbulence by means of an exact hierarchy of structure function equations as well as by direct…

Fluid Dynamics · Physics 2017-05-03 J. Friedrich , H. Homann , T. Schäfer , R. Grauer

Dynamo action is investigated in simulations of locally isotropic and homogeneous turbulence in a slab between open boundaries. It is found that a `pseudo-vacuum' boundary condition (where the field is vertical) leads to strong helicity…

Astrophysics · Physics 2009-10-31 Axel Brandenburg , Wolfgang Dobler

Magnetic helicity is a conserved quantity of ideal magneto-hydrodynamics characterized by an inverse turbulent cascade. Accordingly, it is often invoked as one of the basic physical quantities driving the generation and structuring of…

Magnetic reconnection plays a critical role in many astrophysical processes where high energy emission is observed, e.g. particle acceleration, relativistic accretion powered outflows, pulsar winds and probably in dissipation of Poynting…

Astrophysics · Physics 2010-11-24 G. C. Murphy , Rachid Ouyed , Guy Pelletier

Turbulence is the most common state of astrophysical flows. In typical astrophysical fluids, turbulence is accompanied by strong magnetic fields, which has a large impact on the dynamics of the turbulent cascade. Recently, there has been a…

Astrophysics · Physics 2011-05-10 Jungyeon Cho , A. Lazarian , Ethan Vishniac

Global magnetohydrodynamic (MHD) instabilities are investigated in a computationally tractable two-dimensional model of the solar tachocline. The model's differential rotation yields stability in the absence of a magnetic field, but if a…

Plasma Physics · Physics 2019-02-19 Abigail Plummer , J. B. Marston , S. M. Tobias

Progress toward understanding principles of nonlinear growth and saturation of large scale magnetic fields has emerged from comparison of theoretical models that incorporate the evolution of magnetic helicity with numerical simulations for…

Instrumentation and Methods for Astrophysics · Physics 2015-05-30 Kiwan Park , E. G. Blackman

Numerical test of isotropic turbulence compressibility reduction with helicity in a cyclic box is performed. The ratios of compressibility-relevant-mode spectra over those of kinetic energy present power laws at large wavenumbers in the…

Fluid Dynamics · Physics 2022-11-16 Yan Yang , Jian-Zhou Zhu

As a reduced representation of the nonlinear spectral fluxes of ideal invariants in incompressible magnetohydrodynamics, we construct a gradient-diffusion network model that combines phenomenological considerations and geometrical analysis…

Fluid Dynamics · Physics 2022-03-23 Benjamin Beck , Wolf-Christian Müller

We investigate the transition of the solar wind turbulent cascade from MHD to sub-ion range by means of a detail comparison between in situ observations and hybrid numerical simulations. In particular we focus on the properties of the…

Space Physics · Physics 2020-09-01 L. Matteini , L. Franci , O. Alexandrova , C. Lacombe , S. Landi , P. Hellinger , E. Papini , A. Verdini

We propose a phenomenological theory of incompressible magnetohydrodynamic turbulence in the presence of a strong large-scale magnetic field, which establishes a link between the known anisotropic models of strong and weak MHD turbulence We…

Plasma Physics · Physics 2012-09-21 Roland Grappin , Wolf-Christian Müller , Özgür Gürcan

Rapidly rotating turbulent flow is characterized by the emergence of columnar structures that are representative of quasi-two dimensional behavior of the flow. It is known that when energy is injected into the fluid at an intermediate scale…

Fluid Dynamics · Physics 2015-06-04 Amrik Sen , Pablo D. Mininni , Duane Rosenberg , Annick pouquet

The growth and saturation of magnetic field in conducting turbulent media with large magnetic Prandtl numbers are investigated. This regime is very common in low-density hot astrophysical plasmas. During the early (kinematic) stage, weak…

Astrophysics · Physics 2009-11-07 A. A. Schekochihin , S. C. Cowley , G. W. Hammett , J. L. Maron , J. C. McWilliams

We study the evolution of growth and decay laws for the magnetic field coherence length xi, energy E_M and magnetic helicity H in freely decaying 3D MHD turbulence. We show that with certain assumptions, self-similarity of the magnetic…

Astrophysics · Physics 2007-05-23 Mattias Christensson , Mark Hindmarsh , Axel Brandenburg

Intermittency is investigated using decaying direct numerical simulations of incompressible weak magnetohydrodynamic turbulence with a strong uniform magnetic field ${\bf b_0}$ and zero cross-helicity. At leading order, this regime is…

Chaotic Dynamics · Physics 2014-09-09 Romain Meyrand , Khurom H. Kiyani , Sebastien Galtier

We present high resolution numerical simulations of compressible magnetohydrodynamic (MHD) turbulence. We concentrate on studies of spectra and anisotropy of velocity and density. We describe a technique of separating different…

Astrophysics · Physics 2016-08-30 Jungyeon Cho , A. Lazarian

We present direct numerical simulations and alpha-model simulations of four familiar three-dimensional magnetohydrodynamic (MHD) turbulence effects: selective decay, dynamic alignment, inverse cascade of magnetic helicity, and the helical…

Fluid Dynamics · Physics 2009-11-10 P. D. Mininni , D. C. Montgomery , A. Pouquet

We present numerical studies of 3-dimensional magnetohydrodynamic (MHD) turbulence in a strongly magnetized medium in the extremely relativistic limit, in which the inertia of the charge carriers can be neglected. We have focused on strong…

Astrophysics · Physics 2009-11-10 Jungyeon Cho