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Related papers: Axial dipolar dynamo action in the Taylor-Green vo…

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We investigate an efficient mechanism for generating magnetic fields in turbulent, collisionless plasmas. By using fully kinetic, particle-in-cell simulations of an initially non-magnetized plasma, we inspect the genesis of magnetization,…

Plasma Physics · Physics 2021-12-01 F. Pucci , M. Viviani , F. Valentini , G. Lapenta , W. H. Matthaeus , S. Servidio

The scale (conformal) anomaly can generate an electric current near the boundary of a system in the presence of a static magnetic field. The magnitude of this magnetization current, produced at zero temperature and in the absence of matter,…

High Energy Physics - Lattice · Physics 2023-08-29 M. N. Chernodub , V. A. Goy , A. V. Molochkov

It is usually believed that the geo-dynamo of the Earth or more generally of other planets, is created by the convective fluid motions inside their molten cores. An alternative to this thermal or compositional convection can however be…

Fluid Dynamics · Physics 2016-08-16 P. Le Gal , L. Lacaze , S. Le Dizès

Numerical simulations of the magnetorotational instability (MRI) with zero initial net flux in a non-stratified isothermal cubic domain are used to demonstrate the importance of magnetic boundary conditions.In fully periodic systems the…

High Energy Astrophysical Phenomena · Physics 2011-07-08 Petri J. Käpylä , Maarit J. Korpi

We report the first experimental observation of reversals of a dynamo field generated in a laboratory experiment based on a turbulent flow of liquid sodium. The magnetic field randomly switches between two symmetric solutions B and -B. We…

Galactic dynamo models have generally relied on input parameters that are very challenging to constrain. We address this problem by developing a model that uses observable quantities as input: the galaxy rotation curve, the surface…

Astrophysics of Galaxies · Physics 2024-04-04 Luke Chamandy , Rion Glenn Nazareth , Gayathri Santhosh

The existence of a weak galactic magnetic field has been repeatedly confirmed by observational data. The origin of this field has not as yet been explained in a fully satisfactory way and represents one of the main challenges of the…

Astrophysics · Physics 2009-11-06 Alexander Schekochihin , Stanislav Boldyrev , Russell Kulsrud

A solar-type dynamo model in a spherical shell is developed with allowance for random dependence of the poloidal field generation mechanism on time and latitude. The model shows repeatable epochs of strongly decreased amplitude of magnetic…

Solar and Stellar Astrophysics · Physics 2015-06-17 S. V. Olemskoy , L. L. Kitchatinov

Magnetohydrodynamic turbulence affects both terrestrial and astrophysical plasmas. The properties of magnetized turbulence must be better understood to more accurately characterize these systems. This work presents ideal MHD simulations of…

Fluid Dynamics · Physics 2021-04-28 Forrest W. Glines , Philipp Grete , Brian W. O'Shea

We present numerical simulations of the magnetic field generated by the flow of liquid sodium driven by two counter-rotating impellers (VKS experiment). Using a dynamo kinematic code in cylindrical geometry, it is shown that different…

Fluid Dynamics · Physics 2015-05-13 Christophe Gissinger

Choosing a simple class of flows, with characteristics that may be present in the Earth's core, we study the ability to generate a magnetic field when the flow is permitted to oscillate periodically in time. The flow characteristics are…

Geophysics · Physics 2009-11-10 Ashley P. Willis , David Gubbins

This study investigates, analytically and numerically, the role of an equatorially anti-symmetric lateral variation in heat flux at the outer boundary in polarity transitions in rapidly rotating dynamos. In an unstably stratified fluid, the…

Fluid Dynamics · Physics 2026-03-18 Debarshi Majumder , Binod Sreenivasan

We carried out global three-dimensional magneto-hydrodynamic simulations of dynamo activities in galactic gaseous disks without assuming equatorial symmetry. Numerical results indicate the growth of azimuthal magnetic fields non-symmetric…

Astrophysics of Galaxies · Physics 2015-06-12 Mami Machida , Kenji E. Nakamura , Takahiro Kudoh , Takuya Akahori , Sofue Yoshiaki , Ryoji Matsumoto

Giant planets that reside in close proximity to their host stars are subject to extreme irradiation, which gives rise to thermal ionization of trace Alkali metals in their atmospheres. On objects where the atmospheric electrical…

Earth and Planetary Astrophysics · Physics 2015-06-22 Konstantin Batygin , Sabine Stanley

In this paper, we investigate numerically the flow of an electrically conducting fluid in a cylindrical Taylor-Couette flow when an axial magnetic field is applied. To minimize Ekman recirculation due to vertical no-slip boundaries, two…

Fluid Dynamics · Physics 2015-06-03 Christophe Gissinger , Jeremy Goodman , Hantao Ji

We compare the rigorous equations describing the motion of spinning test particles in gravitational and electromagnetic fields, and show that if the Mathisson-Pirani spin condition holds then exact gravito-electromagnetic analogies emerge.…

General Relativity and Quantum Cosmology · Physics 2016-05-12 L. Filipe O. Costa , José Natário , Miguel Zilhão

We present an effectively global analytical asymptotic galactic dynamo solution for the regular magnetic field of an axisymmetric thin disc in the saturated state. This solution is constructed by combining two well-known types of local…

Astrophysics of Galaxies · Physics 2016-09-02 Luke Chamandy

The generation of magnetic field in an electrically conducting fluid generally involves the complicated nonlinear interaction of flow turbulence, rotation and field. This dynamo process is of great importance in geophysics, planetary…

Fluid Dynamics · Physics 2021-10-04 Steven Tobias

We investigate the nature of the dynamo bifurcation in a configuration applicable to the Earth's liquid outer core. Numerical studies on the stability domain of dipolar magnetic fields found a dichotomy between non-reversing…

Geophysics · Physics 2018-03-14 Ludovic Petitdemange

We consider the nonaxisymmetric modes of instability present in Taylor-Couette flow under the application of helical magnetic fields, mainly for magnetic Prandtl numbers close to the inductionless limit, and conduct a full examination of…

Fluid Dynamics · Physics 2015-10-28 Adam Child , Evy Kersalé , Rainer Hollerbach