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Related papers: The New Mexico alpha-omega Dynamo Experiment: Mode…

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We compare the results of two--dimensional simulations to experimental data obtained at Los Alamos National Laboratory in order to validate the FLASH code. FLASH is a multi--physics, block--structured adaptive mesh refinement code for…

Astrophysics · Physics 2007-05-23 Vikram Dwarkadas , Tomek Plewa , Greg Weirs , Chris Tomkins , Mark Marr-Lyon

We study the formation of coronal jets through numerical simulation of the emergence of a twisted magnetic flux rope into a pre-existing open magnetic field. Reconnection inside the emerging flux rope in addition to that between the…

Solar and Stellar Astrophysics · Physics 2015-06-19 Fang Fang , Yuhong Fan , Scott W. McIntosh

For Sun-like stars, the generation of toroidal magnetic field from poloidal magnetic field is an essential piece of the dynamo mechanism powering their magnetism. Previous authors have estimated the net toroidal flux generated in each…

Solar and Stellar Astrophysics · Physics 2024-01-23 Adam J. Finley , Sacha A. Brun , Antoine Strugarek , Robert Cameron

The next generation dynamo experiment currently under development at Helmholtz-Zentrum Dresden-Rossendorf (HZDR) will consist of a precessing cylindrical container filled with liquid sodium. We perform numerical simulations of kinematic…

Earth and Planetary Astrophysics · Physics 2015-08-11 A. Giesecke , T. Albrecht , G. Gerbeth , T. Gundrum , F. Stefani

The constraint imposed by magnetic helicity conservation on the alpha effect is considered for both magnetically and flow dominated self-organizing plasmas. Direct numerical simulations are presented for a dominant contribution to the alpha…

High Energy Astrophysical Phenomena · Physics 2015-06-18 F. Ebrahimi , A. Bhattacharjee

We demonstrate that a magneto-convection simulation incorporating essential physical processes governing solar surface convection exhibits turbulent small-scale dynamo action. By presenting a derivation of the energy balance equation and…

Solar and Stellar Astrophysics · Physics 2010-04-23 Jonathan Pietarila Graham , Robert Cameron , Manfred Schuessler

Forming massive stars launch outflows of magnetic origin, which in fact serve as a marker for finding sites of massive star formation. However, both the theoretical and observational study of the mechanisms that intervene in the formation…

Solar and Stellar Astrophysics · Physics 2023-01-18 André Oliva , Rolf Kuiper

We present the first kinematic study of an $\alpha\Omega$-dynamo in the General Relativistic Magneto-HydroDynamics (GRMHD) regime, applied to thick disks orbiting around Kerr black holes and using a fully covariant mean field dynamo closure…

High Energy Astrophysical Phenomena · Physics 2015-06-18 M. Bugli , L. Del Zanna , N. Bucciantini

Core convection and dynamo activity deep within rotating A-type stars of 2 solar masses are studied with 3--D nonlinear simulations. Our modeling considers the inner 30% by radius of such stars, thus capturing within a spherical domain the…

Astrophysics · Physics 2008-11-26 Allan Sacha Brun , Matthew K. Browning , Juri Toomre

The VKS experiment has evidenced dynamo action in a highly turbulent liquid sodium von K\'arm\'an flow [R. Monchaux et al., Phys. Rev. Lett. {\bf 98}, 044502 (2007)]. However, the existence and the onset of a dynamo happen to depend on the…

Fluid Dynamics · Physics 2011-06-10 A. Pinter , B. Dubrulle , F. Daviaud , J. Leorat

Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmosphere. In this paper we use helical…

Solar and Stellar Astrophysics · Physics 2011-09-28 Jörn Warnecke , Axel Brandenburg

The global-scale dynamo action achieved in a simulation of a Sun-like star rotating at thrice the solar rate is assessed. The 3-D MHD Anelastic Spherical Harmonic (ASH) code, augmented with a viscosity minimization scheme, is employed to…

Solar and Stellar Astrophysics · Physics 2015-03-17 Kyle Augustson , Sacha Brun , Mark Miesch , Juri Toomre

We present results from three-dimensional non-linear hydrodynamic simulations of a precession driven flow in cylindrical geometry. The simulations are motivated by a dynamo experiment currently under development at Helmholtz-Zentrum…

Fluid Dynamics · Physics 2015-12-09 A. Giesecke , T. Albrecht , T. Gundrum , J. Herault , F. Stefani

Large-scale planetary or stellar magnetic fields generated by a dynamo effect are mostly attributed to flows forced by buoyancy forces in electrically conducting fluid layers. However, these large-scale fields may also be controlled by…

Solar and Stellar Astrophysics · Physics 2015-06-22 David Cébron , Rainer Hollerbach

Increasing observations are becoming available about a relatively weak, but persistent, non-axisymmetric magnetic field co-existing with the dominant axisymmetric field on the Sun. It indicates that the non-axisymmetric magnetic field plays…

Astrophysics · Physics 2008-11-26 J. Jiang , J. X. Wang

Astrophysical jets are launched from strongly magnetized systems that host an accretion disk surrounding a central object. The origin of the magnetic field, which is a key component of the launching process, is still an open question. Here…

High Energy Astrophysical Phenomena · Physics 2023-06-28 Giancarlo Mattia , Christian Fendt

Convective flow in Earth's iron-rich liquid core drives self-sustained dynamo action, generating Earth's magnetic field, which is strongest among all terrestrial planets of the solar system. Rock records show that this magnetic field has…

Earth and Planetary Astrophysics · Physics 2025-08-04 Urmi Dutta , Chris J. Davies , Ashley P. Willis

Context. Solar blowout jets are a distinct subclass of ubiquitous extreme-ultraviolet (EUV) and X-ray coronal jets. Aims. Most existing models of blowout jets prescribe an initial magnetic field configurations and apply ad-hoc changes in…

Solar and Stellar Astrophysics · Physics 2026-02-11 Yajie Chen , Hardi Peter , Damien Przybylski , Lakshmi Pradeep Chitta , Sudip Mandal

Granular material on an inclined plane will flow like a fluid if the angle $\theta$ the plane makes with the horizontal is large enough. We employ a modification of a hydrodynamic model introduced previously to describe Couette flow…

Statistical Mechanics · Physics 2009-11-07 Lyderic Bocquet , Jalal Errami , Tom. C. Lubensky

In many astrophysical environments, self-gravity can generate kinetic energy, which, in principle, is available for driving dynamo action. Using direct numerical simulations, we show that in unstirred self-gravitating subsonic turbulence…

Astrophysics of Galaxies · Physics 2022-04-20 Axel Brandenburg , Evangelia Ntormousi