English
Related papers

Related papers: Testing magnetic helicity conservation in a solar-…

200 papers

We present Direct Numerical Simulations of decaying Magnetohydrodynamic (MHD) turbulence at low magnetic Reynolds number. The domain considered is bounded by periodic boundary conditions in the two directions perpendicular to the magnetic…

Fluid Dynamics · Physics 2015-03-19 Kacper Kornet , Alban Potherat

We present a new magnetohydrodynamic (MHD) code for the simulation of wave propagation in the solar atmosphere, under the effects of electrical resistivity, but not dominant, and heat transference in a uniform 3D grid. The code is based on…

Solar and Stellar Astrophysics · Physics 2017-08-02 Anamaría Navarro , F. D. Lora-Clavijo , Guillermo A. González

Interstellar gas clouds are often both highly magnetized and supersonically turbulent, with velocity dispersions set by a competition between driving and dissipation. This balance has been studied extensively in the context of gases with…

Astrophysics of Galaxies · Physics 2018-01-19 Yuval Birnboim , Christoph Federrath , Mark Krumholz

The metriplectic framework, which permits to formulate an algebraic structure for dissipative systems, is applied to visco-resistive Magneto-Hydrodynamics (MHD), adapting what had already been done for non-ideal Hydrodynamics (HD). The…

Fluid Dynamics · Physics 2015-05-30 Massimo Materassi , Emanuele Tassi

Scale invariance is a hallmark of many natural systems, including solar flares, where energy release spans a vast range of scales. Recent computational advances, at the level of both algorithmics and hardware, have enabled high-resolution…

We present a reduced magnetohydrodynamic (MHD) mathematical model describing the dynamical behavior of highly conducting plasmas with frozen-in magnetic fields, constrained by the assumption that, there exists a frame of reference, where…

Plasma Physics · Physics 2022-02-23 Igor V Sokolov , Lulu Zhao , Tamas I Gombosi

We provide a valid magnetohydrostatic equilibrium from the collapse of a 2D X-point in the presence of a finite plasma pressure, in which the current density is not simply concentrated in an infinitesimally thin, one-dimensional current…

Solar and Stellar Astrophysics · Physics 2013-09-13 Jorge Fuentes-Fernández , Clare E. Parnell , Alan W. Hood

The nonlinear dynamics of magnetic helicity, $H^M$, which is responsible for large-scale magnetic structure formation in electrically conducting turbulent media is investigated in forced and decaying three-dimensional magnetohydrodynamic…

Fluid Dynamics · Physics 2015-06-03 Wolf-Christian Müller , Shiva Kumar Malapaka , Angela Busse

By defining an appropriate field line helicity, we apply the powerful concept of magnetic helicity to the problem of global magnetic field evolution in the Sun's corona. As an ideal-magnetohydrodynamic invariant, the field line helicity is…

Solar and Stellar Astrophysics · Physics 2017-07-05 A. R. Yeates , G. Hornig

The Parker conjecture, which explores whether magnetic fields in perfectly conducting plasmas can develop tangential discontinuities during magnetic relaxation, remains an open question in astrophysics. Helicity conservation provides a…

Numerical Analysis · Mathematics 2025-11-11 Mingdong He , Patrick E. Farrell , Kaibo Hu , Boris D. Andrews

We extend our recent derivation of the time evolution equations for the energy content of magnetic fields and turbulent motions for incompressible, homogeneous, and isotropic turbulence to include the case of nonvanishing helicity. These…

Cosmology and Nongalactic Astrophysics · Physics 2013-06-14 Andrey Saveliev , Karsten Jedamzik , Guenter Sigl

The process of current filamentation in permanently externally driven, initially globally ideal plasmas is investigated by means of two-dimensional Magnetohydrodynamic (MHD)-simulations. This situation is typical for astrophysical systems…

Astrophysics · Physics 2009-10-31 C. Konz , H. Wiechen , H. Lesch

We examine the range of rest-mass densities, temperatures and magnetic fields involved in simulations of binary neutron star mergers (BNSM) and identify the conditions under which the ideal magneto-hydrodynamics (MHD) breaks down using…

High Energy Astrophysical Phenomena · Physics 2019-07-12 Arus S. Harutyunyan

Dynamo processes are ubiquitous in astrophysical systems. In relativistic astrophysical systems, such as accretion disks around black holes or neutron stars, they may critically affect the launching of winds and jets that can power…

High Energy Astrophysical Phenomena · Physics 2025-07-31 Jiaxi Wu , Elias R. Most

We study the evolution of a stochastic helical magnetic field generated in the early Universe after the electroweak phase transition, using standard magnetohydrodynamics (MHD). We find how the coherence length xi, magnetic energy E_M and…

Astrophysics · Physics 2017-08-23 Mark Hindmarsh , M. Christensson , A. Brandenburg

We develop structure-preserving finite element methods for the incompressible, resistive Hall magnetohydrodynamics (MHD) equations. These equations incorporate the Hall current term in Ohm's law and provide a more appropriate description of…

Numerical Analysis · Mathematics 2022-02-24 Fabian Laakmann , Patrick E. Farrell , Kaibo Hu

We develop a two-scale formalism to determine global magnetic helicity spectra in systems where the local magnetic helicity has opposite signs on both sides of the equator, giving rise to cancelation with conventional methods. We verify…

Solar and Stellar Astrophysics · Physics 2017-02-07 Axel Brandenburg , Gordon J. D. Petrie , Nishant K. Singh

We propose two sets of initial conditions for magnetohydrodynamics (MHD) in which both the velocity and the magnetic fields have spatial symmetries that are preserved by the dynamical equations as the system evolves. When implemented…

Fluid Dynamics · Physics 2009-11-13 E. Lee , M. E. Brachet , A. Pouquet , P. D. Mininni , D. Rosenberg

Motivated by a scenario of magnetogenesis in which a homogeneous magnetic field is generated during inflation, we study the magnetohydrodynamic evolution of the primordial plasma motions for two kinds of initial conditions -- (i) a…

Cosmology and Nongalactic Astrophysics · Physics 2020-07-28 Axel Brandenburg , Ruth Durrer , Yiwen Huang , Tina Kahniashvili , Sayan Mandal , Shinji Mukohyama

The appearance of eruptive space plasma processes, e.g., in eruptive flares as observed in the solar atmosphere, is usually assumed to be caused by magnetic reconnection. The process of magnetic reconnection is often connected with singular…

Solar and Stellar Astrophysics · Physics 2009-09-07 Dieter Nickeler , Marian Karlicky , Miroslav Barta