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Related papers: Kinematic dynamos in triaxial ellipsoids

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The elliptical instability can take place in planetary cores and stars elliptically deformed by gravitational effects, where it generates large-scale three-dimensional flows assumed to be dynamo capable. In this work, we present the first…

Classical Physics · Physics 2013-09-10 David Cébron , Michael Le Bars , Pierre Maubert , Patrice Le Gal

Dynamo action in planetary cores has been extensively studied in the context of convectively-driven flows. We show in this letter that mechanical forcings, namely tides, libration and precession, are also able to kinematically sustain a…

Fluid Dynamics · Physics 2018-11-07 K. Sandeep Reddy , Benjamin Favier , Michael Le Bars

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

We numerically examine dynamo action generated by a flow of an electrically conducting fluid in a precessing cylindrical cavity. We compare a simplified kinematic approach based on the solution of the magnetic induction equation with a…

Fluid Dynamics · Physics 2025-04-07 André Giesecke , Mike Wilbert , Ján Šimkanin , Rainer Grauer , Frank Stefani

The experimental realization of dynamo excitation as well as theoretical and numerical examinations of the induction equation have shown the relevance of boundary conditions for a self-sustaining dynamo. Within the interior of a field…

Fluid Dynamics · Physics 2012-08-08 Andre Giesecke , Frank Stefani , Gunter Gerbeth

We numerically demonstrate the feasibility of kinematic fast dynamos for a class of time-periodic axisymmetric flows of conducting fluid confined inside a sphere. The novelty of our work is in considering the realistic flows, which are…

Plasma Physics · Physics 2013-09-19 I. V. Khalzov , C. M. Cooper , C. B. Forest

We consider the classical problem of kinematic dynamo action in simple steady flows. Due to the adjointness of the induction operator, we show that the growth rate of the dynamo will be exactly the same for two types of magnetic boundary…

Fluid Dynamics · Physics 2013-09-25 B. Favier , M. R. E. Proctor

The axisymmetric kinematic dynamo problem is reconsidered and a number of open questions are answered. Apart from axisymmetry and smoothness of data and solution we deal with this problem under quite general conditions, i.e. we assume a…

Solar and Stellar Astrophysics · Physics 2019-09-30 Ralf Kaiser , Andreas Tilgner

We investigate free hydromagnetic eigenmodes of an incompressible, inviscid and ideal electrically conducting fluid in rotating triaxial ellipsoids. The container rotates with an angular velocity tilted from its figure. The magnetic base…

Fluid Dynamics · Physics 2017-02-24 Jérémie Vidal , David Cébron , Nathanaël Schaeffer

We use three-dimensional direct numerical simulations of the helically forced magnetohydrodynamic equations in spherical shell segments in order to study the effects of changes in the geometrical shape and size of the domain on the growth…

Astrophysics · Physics 2010-01-15 Dhrubaditya Mitra , Reza Tavakol , Axel Brandenburg , David Moss

The kinematic dynamo problem is investigated for the flow of a conducting fluid in a cylindrical, periodic tube with conducting walls. The methods used are an eigenvalue analysis of the steady regime, and the three-dimensional solution of…

Astrophysics · Physics 2009-11-07 Wolfgang Dobler , Peter Frick , Rodion Stepanov

Understanding the origin and evolution of magnetic fields on cosmological scales opens up a window into the physics of the early Universe. Numerical simulations of such fields require a careful treatment to faithfully solve the equations of…

Cosmology and Nongalactic Astrophysics · Physics 2025-08-28 Nikyta Shchutskyi , Matthieu Schaller , Orestis A. Karapiperis , Federico A. Stasyszyn , Axel Brandenburg

Magnetic fields pervade astrophysical systems and strongly influence their dynamics. Because magnetic diffusion is usually much faster than system evolution, ancient fields cannot explain the present magnetization of planets, stars, and…

Earth and Planetary Astrophysics · Physics 2025-12-11 Albert Elias-López

Cosmic kinematic fast dynamo is found in non-inflationary phases of an ellipsoidal anisotropic cosmological metric background solution of Einstein field equations of general relativity. The magnetic field is amplified inside the universe…

General Relativity and Quantum Cosmology · Physics 2007-07-13 L. C. Garcia de Andrade

This paper outlines a numerical algorithm that could be used for simulating full 3D dynamics of magnetic fluid droplet shapes in external magnetic fields, by solving boundary integral equations. The algorithm works with arbitrary droplet…

Fluid Dynamics · Physics 2022-03-18 Aigars Langins , Andris P. Stikuts , Andrejs Cēbers

The homogeneous dynamo effect is at the root of cosmic magnetic field generation. With only a very few exceptions, the numerical treatment of homogeneous dynamos is carried out in the framework of the differential equation approach. The…

Astrophysics · Physics 2009-11-10 Mingtian Xu , Frank Stefani , Gunter Gerbeth

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

The conventional magnetic induction equation that governs hydromagnetic dynamo action is transformed into an equivalent integral equation system. An advantage of this approach is that the computational domain is restricted to the region…

Astrophysics · Physics 2009-06-23 Mingtian Xu , Frank Stefani , Gunter Gerbeth

We numerically investigate the efficiency of a spherical Couette flow at generating a self-sustained magnetic field. No dynamo action occurs for axisymmetric flow while we always found a dynamo when non-axisymmetric hydrodynamical…

Geophysics · Physics 2020-07-17 Céline Guervilly , Philippe Cardin

Context. Earlier work has suggested that large-scale dynamos can reach and maintain equipartition field strengths on a dynamical time scale only if magnetic helicity of the fluctuating field can be shed from the domain through open…

Solar and Stellar Astrophysics · Physics 2011-07-08 P. J. Käpylä , M. J. Korpi , A. Brandenburg
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