English
Related papers

Related papers: Identification of vortexes obstructing the dynamo …

200 papers

We present an elegant method of determining the eigensolutions of the induction and the dynamo equation in a fluid embedded in a vacuum. The magnetic field is expanded in a complete set of functions. The new method is based on the…

Instrumentation and Methods for Astrophysics · Physics 2015-05-14 M. Schrinner , D. Schmitt , J. Jiang , P. Hoyng

Photospheric vortex flows are thought to play a key role in the evolution of magnetic fields. Recent studies show that these swirling motions are ubiquitous in the solar surface convection and occur in a wide range of temporal and spatial…

Solar and Stellar Astrophysics · Physics 2018-03-07 Iker S. Requerey , Basilio Ruiz Cobo , Milan Gošić , Luis R. Bellot Rubio

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

Feature identification is an important task in many fluid dynamics applications and diverse methods have been developed for this purpose. These methods are based on a physical understanding of the underlying behavior of the flow in the…

Fluid Dynamics · Physics 2019-01-07 Carlos Michelén Ströfer , Jinlong Wu , Heng Xiao , Eric Paterson

The current understanding of astrophysical magnetic fields is reviewed, focusing on their generation and maintenance by turbulence. In the astrophysical context this generation is usually explained by a self-excited dynamo, which involves…

Astrophysics · Physics 2008-11-26 Axel Brandenburg , Kandaswamy Subramanian

The magnetic field measured in the Madison Dynamo Experiment shows intermittent periods of growth when an axial magnetic field is applied. The geometry of the intermittent field is consistent with the fastest growing magnetic eigenmode…

Plasma Physics · Physics 2009-11-11 M. D. Nornberg , E. J. Spence , R. D. Kendrick , C. M. Jacobson , C. B. Forest

Astrophysical objects with negligible resistivity are often threaded by large scale magnetic fields. The generation of these fields is somewhat mysterious, since a magnetic field in a perfectly conducting fluid cannot change the flux…

Astrophysics · Physics 2007-05-23 E. T. Vishniac , A. Lazarian , J. Cho

In this thesis, we consider the dynamics of vortices in the easy plane insulating ferromagnet in two dimensions. In addition to the quasiparticle excitations, here spin waves or magnons, this magnetic system admits a family of vortex…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Lara Thompson

In the present paper, we study a new type of large-scale instability, which arises in obliquely rotating electroconductive fluids with a small-scale external force of zero helicity. This force excites small-scale velocity oscillations with…

Plasma Physics · Physics 2017-11-27 M. I. Kopp , A. V. Tur , V. V. Yanovsky

Turbulent flows of incompressible liquid in two dimensions are comprised of dense systems of vortices. Such system of vortices can be treated as a fluid and itself could be described in terms of hydrodynamics. We develop the hydrodynamics…

Fluid Dynamics · Physics 2014-09-11 Paul Wiegmann , Alexander G. Abanov

At high densities fluids of strongly dipolar spherical particles exhibit spontaneous long-ranged orientational order. Typically, due to demagnetization effects induced by the long range of the dipolar interactions, the magnetization…

Soft Condensed Matter · Physics 2009-10-30 B. Groh , S. Dietrich

Dynamo action refers to energy exchange processes through which magnetic fields are generated at the expense of kinetic energy of the plasma flows. Dynamos can generate magnetic fields across scales larger or smaller than the flows…

Numerical experiments of dynamo action designed to understand the generation of Earth's magnetic field produce different regime branches identified within bifurcation diagrams. Notable are distinct branches where the resultant magnetic…

Geophysics · Physics 2025-08-11 Robert J. Teed , Emmanuel Dormy

Vortex rings are remarkably stable structures occurring in numerous systems: for example in turbulent gases, where they are at the origin of weather phenomena [1]; in fluids with implications for biology [2]; in electromagnetic discharges…

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 propose a new self-consistent dynamo mechanism for the generation of large-scale magnetic fields in natural objects. Recent computational studies have described the formation of large-scale vortices (LSVs) in rotating turbulent…

Fluid Dynamics · Physics 2015-06-24 Celine Guervilly , David W. Hughes , Chris A. Jones

The energy of a displaced magnetic vortex in a cylindrical particle made of isotropic ferromagnetic material (magnetic dot) is calculated taking into account the magnetic dipolar and the exchange interactions. Under the simplifying…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Konstantin Yu. Guslienko , Konstantin L. Metlov

Natural dynamos such as planets and stars generate global scale magnetic field despite the inferred presence of small scale turbulence. Such systems are known as large scale dynamos and are typically driven by convection and influenced by…

Fluid Dynamics · Physics 2022-02-24 Ming Yan , Michael A. Calkins

Initial results from the Madison Dynamo Experiment provide details of the inductive response of a turbulent flow of liquid sodium to an applied magnetic field. The magnetic field structure is reconstructed from both internal and external…

Plasma Physics · Physics 2007-05-23 M. D. Nornberg , E. J. Spence , R. D. Kendrick , C. M. Jacobson , C. B. Forest

We consider a phase-separating mixture of active and passive fluids and explore morphological asymmetries of the emerging dominantly bicontinous dynamic emulsion. Two-dimensional numerical simulations reveal that the geometric and…

Soft Condensed Matter · Physics 2026-01-22 Rainer Backofen , Axel Voigt