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Related papers: Numerical Simulations of Dynamos Generated in Sphe…

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We present axisymmetric numerical calculations of the fluid flow induced in a spherical shell with inner sphere rotating and outer sphere stationary. A magnetic field is also imposed, consisting of particular linear combinations of axial…

Earth and Planetary Astrophysics · Physics 2010-08-03 Xing Wei , Rainer Hollerbach

We present a high-order numerical study of the dependence of the dynamo onset on different electromagnetic boundary conditions, in convecting Boussinesq flows forced by a temperature gradient. Perfectly conducting boundaries, vacuum, and…

Fluid Dynamics · Physics 2023-03-21 Mauro Fontana , Pablo D. Mininni , Pablo Dmitruk

Polarity reversals are a key feature of Earth's magnetic field, yet the processes governing them are still poorly understood. Dipole reversals have been found in many numerical dynamo simulations and often occur close to the transition…

Geophysics · Physics 2025-05-13 Andrew T. Clarke , Christopher J. Davies , Souvik Naskar , Stephen J. Mason

We present numerical investigations into three principal properties of the small-scale dynamo in stably stratified turbulence: the onset criterion, the growth rate, and the nature of the magnetic field anisotropy in the kinematic regime.…

Fluid Dynamics · Physics 2021-02-04 Valentin Skoutnev , Jonathan Squire , Amitava Bhattacharjee

A magnetic dynamo experiment is under construction at the New Mexico Institute of Mining and Technology. The experiment is designed to demonstrate in the laboratory the alpha-omega magnetic dynamo, which is believed to operate in many…

Astrophysics · Physics 2009-09-25 S. A. Colgate , V. I. Pariev , H. F. Beckley , R. Ferrel , V. D. Romero , J. C. Weatherall

The rheology of 2D steady surface flow of cohesionless cylinders in a rotating drum is investigated through {\em Non Smooth Contact Dynamics} simulations. Profile of volume fraction, translational and angular velocity, rms velocity, strain…

Soft Condensed Matter · Physics 2007-05-23 Mathieu Renouf , Daniel Bonamy , Frederic Dubois , Pierre Alart

The linear stability of MHD Taylor-Couette flow of infinite vertical extension is considered for various magnetic Prandtl numbers Pm. The calculations are performed for a wide gap container with \hat\eta=0.5 with an axial uniform magnetic…

Astrophysics · Physics 2016-08-16 D. A. Shalybkov , G. Rüdiger , M. Schultz

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

In this study we discuss two key issues related to a small-scale dynamo instability at low magnetic Prandtl numbers and large magnetic Reynolds numbers, namely: (i) the scaling for the growth rate of small-scale dynamo instability in the…

Solar and Stellar Astrophysics · Physics 2015-06-03 N. Kleeorin , I. Rogachevskii

We consider the generation of magnetic activity --- dynamo waves --- in the astrophysical limit of very large magnetic Reynolds number. We consider kinematic dynamo action for a system consisting of helical flow and large-scale shear. We…

Solar and Stellar Astrophysics · Physics 2015-06-19 Fausto Cattaneo , Steven Tobias

We consider the linear stability of dissipative MHD Taylor-Couette flow with imposed toroidal magnetic fields. The inner and outer cylinders can be either insulating or conducting; the inner one rotates, the outer one is stationary. The…

Astrophysics · Physics 2009-11-11 G. Ruediger , M. Schultz , D. Shalybkov , R. Hollerbach

A series of direct numerical simulations in large computational domains has been performed in order to probe the spatial feature robustness of the Taylor rolls in turbulent Taylor-Couette (TC) flow. The latter is the flow between two…

Fluid Dynamics · Physics 2017-04-21 Rodolfo Ostilla-Mónico , Detlef Lohse , Roberto Verzicco

We present dynamos computed using a hybrid QG-3D numerical scheme in a thick spherical shell geometry. Our model is based on a quasi-geostrophic convection code extended with a 3D treatment of heat transport and magnetic induction. We find…

Geophysics · Physics 2023-12-18 Olivier Barrois , Thomas Gastine , Christopher C. Finlay

Recent experiments have shown that it is possible to study a fundamental astrophysical process such as dynamo action in controlled laboratory conditions using simple MHD flows. In this paper we explore the possibility that Taylor-Couette…

Astrophysics · Physics 2009-11-07 Ashley P. Willis , Carlo F. Barenghi

Rayleigh-B\'enard convection in rotating spherical shells can be considered as a simplified analogue of many astrophysical and geophysical fluid flows. Here, we use three-dimensional direct numerical simulations to study this physical…

Fluid Dynamics · Physics 2016-11-23 T. Gastine , J. Wicht , J. Aubert

We present direct numerical simulations of reversals of the magnetic field generated by swirling flows in a spherical domain. In agreement with a recent model, we observe that coupling dipolar and quadrupolar magnetic modes by an asymmetric…

Fluid Dynamics · Physics 2015-05-13 Christophe Gissinger , Emmanuel Dormy , Stephan Fauve

The present-day Universe is highly magnetized, even though the first magnetic seed fields were most probably extremely weak. To explain the growth of the magnetic field strength over many orders of magnitude fast amplification processes…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Jennifer Schober , Dominik Schleicher , Stefano Bovino , Ralf S. Klessen

Many exact coherent states (ECS) arising in wall-bounded shear flows have an asymptotic structure at extreme Reynolds number Re in which the effective Reynolds number governing the streak and roll dynamics is O(1). Consequently, these…

Fluid Dynamics · Physics 2023-07-19 Brandon Montemuro , Christopher M. White , Joseph C. Klewicki , Gregory P. Chini

The dynamics of fluctuations in a fast rotating spherical Couette flow experiment in the presence of a strong dipolar magnetic field is investigated in detail, through a thorough analysis of the experimental data as well as a numerical…

Geophysics · Physics 2016-01-22 Denys Schmitt , Philippe Cardin , Patrick La Rizza , Henri-Claude Nataf

The DTS experiment is a spherical Couette flow experiment with an imposed dipolar magnetic field. Liquid sodium is used as a working fluid. In a series of measurement campaigns, we have obtained data on the mean axisymmetric velocity, the…

Fluid Dynamics · Physics 2015-06-11 Henri-Claude Nataf