English
Related papers

Related papers: Turbulent magnetic decay controlled by two conserv…

200 papers

We use 3D numerical MHD simulations to follow the evolution of cold, turbulent, gaseous systems with parameters representing GMC conditions. We study three cloud simulations with varying mean magnetic fields, but identical initial velocity…

Astrophysics · Physics 2008-11-26 Eve C. Ostriker , James M. Stone , Charles F. Gammie

Magnetic helicity, and more broadly magnetic field line topology, impose constraints on the plasma dynamics. Helically interlocked magnetic rings are in a non-trivial topological state. It is harder to bring them into a topologically…

Plasma Physics · Physics 2024-12-09 Simon Candelaresi , Fabio Del Sordo

We compare the helical and nonhelical (magneto-)Burgers turbulence for the \textit{helicity fastening effect}. Theoretical arguments and heuristic mathematical analysis are offered for the latter notion in the new system loosing some…

Fluid Dynamics · Physics 2023-08-21 Jian-Zhou Zhu , Pei-Xin Shi

Decay of honeycomb-generated turbulence in a duct with a static transverse magnetic field is studied via direct numerical simulations. The simulations follow the revealing experimental study of Sukoriansky et al. (1986), in particular the…

Fluid Dynamics · Physics 2019-05-01 Oleg Zikanov , Dmitry Krasnov , Thomas Boeck , Semion Sukoriansky

We study the magnetic field to density ($B-\rho$) relation in turbulent molecular clouds with dynamically important magnetic fields using nonideal three-dimensional magnetohydrodynamic simulations. Our simulations show that there is a…

Astrophysics of Galaxies · Physics 2022-03-30 Sayantan Auddy , Shantanu Basu , Takahiro Kudoh

We present calculations of the relaxation of magnetic field structures that have the shape of particular knots and links. A set of helical magnetic flux configurations is considered, which we call $n$-foil knots of which the trefoil knot is…

Solar and Stellar Astrophysics · Physics 2015-03-19 Simon Candelaresi , Axel Brandenburg

Freely decaying relativistic force-free turbulence is studied for the first time. We initiate the magnetic field at a short wavelength and simulate its relaxation toward equilibrium on two and three dimensional periodic domains, in both…

High Energy Astrophysical Phenomena · Physics 2016-02-02 Jonathan Zrake , William E. East

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

We investigate the influence of a uniform magnetic field ${\bf B_0}=B_0 e//$ on energy decay laws in incompressible magnetohydrodynamic (MHD) turbulence. The nonlinear transfer reduction along $B_0$ is included in a model that distinguishes…

Fluid Dynamics · Physics 2009-11-13 Barbara Bigot , Sebastien Galtier , Helene Politano

Aims. We investigated plasma turbulence in the context of solar wind. We concentrated on properties of ideal second-order magneto-hydrodynamic (MHD) and Hall MHD invariants. Methods. We studied the results of a two-dimensional hybrid…

Plasma Physics · Physics 2026-03-03 Petr Hellinger , Victor Montagud-Camps

The excitation and further sustenance of large-scale magnetic fields in rotating astrophysical systems, including planets, stars and galaxies, is generally thought to involve a fluid magnetic dynamo effect driven by helical…

Fluid Dynamics · Physics 2021-12-10 F. Rincon

Based on micromagnetic simulations, we report on a novel helical magnetic structure in a soft magnetic film that is sandwiched between and exchange-coupled to two hard magnetic layers. Confined between antiparallel hard magnetic moments, a…

Materials Science · Physics 2014-12-04 L. V. Dzemiantsova , G. Meier , R. Röhlsberger

The inverse cascade in MHD turbulence plays a crucial role in various astrophysical processes such as galaxy cluster formation, solar and stellar dynamo mechanisms, and the evolution of primordial magnetic fields in the early universe. A…

Cosmology and Nongalactic Astrophysics · Physics 2026-02-02 Jiyao Zhang , Axel Brandenburg

Using the results of laboratory experiments and direct numerical simulations, as well as observations of the full-disc solar magnetic field and sunspot number dynamics, it is demonstrated that cross-helicity can dominate the frequency power…

Fluid Dynamics · Physics 2025-10-16 A. Bershadskii

Direct numerical simulations of decaying and forced magnetohydrodynamic (MHD) turbulence without and with mean magnetic field are analyzed by higher-order two-point statistics. The turbulence exhibits statistical anisotropy with respect to…

Plasma Physics · Physics 2009-11-10 Wolf-Christian Mueller , Dieter Biskamp , Roland Grappin

In rapidly rotating turbulence (Rossby number much less than unity), the standard mixing length theory for turbulent convection breaks and Coriolis force enters the force balance such that magnetic field eventually depends on rotation. By…

Solar and Stellar Astrophysics · Physics 2022-02-16 Xing Wei

We propose a mechanism for the fast dissipation of magnetic fields which is effective in a stratified medium where ion motions can be neglected. In such a medium, the field is frozen into the electrons and Hall currents prevail. Although…

Astrophysics · Physics 2009-10-31 S. I. Vainshtein , S. M. Chitre , A. V. Olinto

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

We present numerical simulations of driven magnetohydrodynamic (MHD) turbulence with weak/moderate imposed magnetic fields. The main goal is to clarify dynamics of magnetic field growth. We also investigate the effects of the imposed…

Astrophysics · Physics 2011-02-11 J. Cho , E. Vishniac , A. Beresnyak , A. Lazarian , D. Ryu

The question of whether a dynamo can be triggered by gravitational collapse is of great interest, especially for the early Universe. Here, we employ supercomoving coordinates to study the magnetic field amplification from decaying…

Astrophysics of Galaxies · Physics 2025-09-11 Axel Brandenburg , Evangelia Ntormousi