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Related papers: Nonlinear dynamos at infinite magnetic Prandtl num…

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We have carried out high resolution MHD simulations of the nonlinear evolution of Kelvin-Helmholtz unstable flows in 2 1/2 dimensions. The modeled flows and fields were initially uniform except for a thin shear layer with a hyperbolic…

Astrophysics · Physics 2009-10-30 T. W. Jones , Joseph B. Gaalaas , Dongsu Ryu , Adam Frank

The stability of shear flows of electrically conducting fluids, with respect to finite amplitude three-dimensional localized disturbances is considered. The time evolution of the fluid impulse integral, characterizing such disturbances, for…

Fluid Dynamics · Physics 2016-09-08 V. Levinski , I. Rapoport , J. Cohen

We present a numerical study of the magnetic field generated by an axisymmetrically forced flow in a spherical domain. At small enough Reynolds number, Re, the flow is axisymmetric and generates an equatorial dipole above a critical…

Fluid Dynamics · Physics 2009-11-13 Christophe Gissinger , Emmanuel Dormy , Stephan Fauve

MHD turbulence at low Magnetic Reynolds number is experimentally investigated by studying a liquid metal flow in a cubic domain. We focus on the mechanisms that determine whether the flow is quasi-2D, 3D or in any intermediate state. To…

Fluid Dynamics · Physics 2015-05-19 A. Pothérat , R. Klein

The MHD flow driven by a travelling magnetic field (TMF) in an annular channel is investigated numerically. For sufficiently large magnetic Reynolds number Rm, or if a large enough pressure gradient is externally applied, the system…

Fluid Dynamics · Physics 2016-03-23 Christophe Gissinger , Paola Rodriguez-Imazio , Stephan Fauve

The dynamo driven by the magnetorotational instability (MRI) is believed to play an important role in the dynamics of accretion discs and may also explain the origin of the extreme magnetic fields present in magnetars. Its saturation level…

High Energy Astrophysical Phenomena · Physics 2022-09-21 Jerome Guilet , Alexis Reboul-Salze , Raphael Raynaud , Matteo Bugli , Basile Gallet

We analyze direct numerical simulations of large-scale dynamos in inhomogeneous nonhelically driven rotating turbulence with and without shear. The forcing is modulated so that the turbulent intensity peaks in the middle of the…

Plasma Physics · Physics 2025-05-02 Axel Brandenburg , Ethan T. Vishniac

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

In this paper, we find a new large scale instability displayed by a stratified rotating flow in forced turbu- lence. The turbulence is generated by a small scale external force at low Reynolds number. The theory is built on the rigorous…

Fluid Dynamics · Physics 2013-11-13 Anatoly Tur , Malik Chabane , Vladimir Yanovsky

The research is devoted to the stability of convective flow in a nonuniformly rotating layer of an electrically conducting fluid in a spiral magnetic field. The stationary and oscillatory modes of magnetic convection are considered…

Plasma Physics · Physics 2019-05-15 M. I. Kopp , A. V. Tur , V. V. Yanovsky

The flow transformation and the generation of vortex structures by a strong magnetic dipole field in a liquid metal duct flow is studied by means of three-dimensional direct numerical simulations. The dipole is considered as the paradigm…

Fluid Dynamics · Physics 2013-11-13 Saskia Tympel , Thomas Boeck , Jörg Schumacher

Amplification of magnetic field due to kinematic turbulent dynamo action is studied in the regime of small magnetic Prandtl numbers. Such a regime is relevant for planets and stars interiors, as well as for liquid metal laboratory…

Solar and Stellar Astrophysics · Physics 2015-05-20 Leonid M. Malyshkin , Stanislav Boldyrev

We calculate the mean electromotive force in plane Couette flows of a nonrotating conducting fluid under the influence of a large-scale magnetic field for driven turbulence. A vertical stratification of the turbulence intensity results in…

Solar and Stellar Astrophysics · Physics 2014-08-12 G. Ruediger , A. Brandenburg

This work concentrates on the effect of an irrotational forcing on a magnetized flow in the presence of rotation, baroclinicity, shear, or a combination of them. By including magnetic field in the model we can evaluate the occurrence of…

Astrophysics of Galaxies · Physics 2023-09-08 Albert Elias-López , Fabio Del Sordo , Daniele Viganò

This work studies the effectiveness of several machine learning techniques for predicting extreme events occurring in the flow around an airfoil at low Reynolds. For certain Reynolds numbers the aerodynamic forces exhibit intermittent…

Fluid Dynamics · Physics 2021-08-13 Samuel H. Rudy , Themistoklis P. Sapsis

The small-scale dynamo is typically studied by assuming that the correlation time of the velocity field is zero. Some authors have used a smooth renovating flow model to study how the properties of the dynamo are affected by the correlation…

Astrophysics of Galaxies · Physics 2024-05-01 Kishore Gopalakrishnan , Nishant K Singh

The surface shear viscosity of an insoluble surfactant monolayer often depends strongly on its surface pressure. Here, we show that a particle moving within a bounded monolayer breaks the kinematic reversibility of low-Reynolds-number…

Soft Condensed Matter · Physics 2017-09-25 Harishankar Manikantan , Todd M. Squires

Precession has been proposed as an alternative power source for planetary dynamos. Previous hydrodynamic simulations suggested that precession can generate very complex flows in planetary liquid cores [Y. Lin, P. Marti, and J. Noir,…

Fluid Dynamics · Physics 2016-07-27 Yufeng Lin , Philippe Marti , Jerome Noir , Andrew Jackson

We consider the dynamics of a vertically stratified, horizontally-forced Kolmogorov flow. Motivated by astrophysical systems where the Prandtl number is often asymptotically small, our focus is the little-studied limit of high Reynolds…

Fluid Dynamics · Physics 2020-10-27 L. Cope , P. Garaud , C. P. Caulfield

The small-scale dynamo is a process by which turbulent kinetic energy is converted into magnetic energy, and thus is expected to depend crucially on the nature of turbulence. In this work, we present a model for the small-scale dynamo that…

Cosmology and Nongalactic Astrophysics · Physics 2015-05-30 Jennifer Schober , Dominik Schleicher , Christoph Federrath , Ralf Klessen , Robi Banerjee