English
Related papers

Related papers: Kinematic dynamos in triaxial ellipsoids

200 papers

The three-dimensional (3D) full compressible magnetohydrodynamic system is studied in a general bounded domain with slip boundary condition for the velocity filed, adiabatic condition for the temperature and perfect conduction for the…

Analysis of PDEs · Mathematics 2022-08-10 Yazhou Chen , Yunkun Chen , Xue Wang

Exploring the origin and properties of magnetic fields is crucial to the development of many fields such as physics, astronomy and meteorology. We focus on the edge element approximation and theoretical analysis of celestial dynamo system…

Numerical Analysis · Mathematics 2023-07-10 Junqing Chen , Ming Sun

We present a new scenario for magnetic field amplification where an electrically conducting fluid is confined in a differentially rotating, spherical shell with thin aspect-ratio. When the angular momentum sufficiently decreases outwards,…

Fluid Dynamics · Physics 2016-06-14 Florence Marcotte , Christophe Gissinger

We have performed numerical simulations of boundary-driven dynamos using a three-dimensional non-linear magnetohydrodynamical model in a spherical shell geometry. A conducting fluid of magnetic Prandtl number Pm=0.01 is driven into motion…

Fluid Dynamics · Physics 2012-11-02 Céline Guervilly , Nicholas H. Brummell

The conditions imposed in the paper ['Inertial manifolds and completeness of eigenmodes for unsteady magnetic dynamos', Physica D {\bf 194} (2004) 297-319] on the fluid velocity to guarantee the existence of inertial manifolds for the…

Plasma Physics · Physics 2007-05-23 Manuel Nunez

We present a computational method to solve the magnetohydrodynamic equations in spherical geometry. The technique is fully nonlinear and wholly spectral, and uses an expansion basis that is adapted to the geometry: Chandrasekhar-Kendall…

Fluid Dynamics · Physics 2009-11-11 P. D. Mininni , D. C. Montgomery

Spiral galaxies, including the Milky Way, have large-scale magnetic fields with significant energy densities. The dominant theory attributes these magnetic fields to a large-scale dynamo. We review the current status of dynamo theory and…

Astrophysics of Galaxies · Physics 2023-08-31 Axel Brandenburg , Evangelia Ntormousi

Most large-scale planetary magnetic fields are thought to be driven by low Rossby number convection of a low magnetic Prandtl number fluid. Here kinematic dynamo action is investigated with an asymptotic, rapidly rotating dynamo model for…

Geophysics · Physics 2016-12-14 Michael A. Calkins , Louie Long , David Nieves , Keith Julien , Steven M. Tobias

The kinematic induction equation of MHD is solved numerically in the case of the normal ``111'' ABC flow using a general staggered mesh method. Careful 3-D visualizations of the topology of the magnetic field reveal that previous…

Astrophysics · Physics 2009-10-31 S. B. F. Dorch

Numerical MHD simulations play increasingly important role for understanding mechanisms of stellar magnetism. We present simulations of convection and dynamos in density-stratified rotating spherical fluid shells. We employ a new 3D…

Solar and Stellar Astrophysics · Physics 2015-09-03 Radostin D. Simitev , Alexander G. Kosovichev , Friedrich H. Busse

We investigate numerically magnetic field generation by thermal convection with square periodicity cells in a rotating horizontal layer of electrically-conducting fluid with stress-free electrically perfectly conducting boundaries for…

Chaotic Dynamics · Physics 2010-04-12 V. Zheligovsky

We propose a plasma experiment to be used to investigate fundamental properties of astrophysical dynamos. The highly conducting, fast-flowing plasma will allow experimenters to explore systems with magnetic Reynolds numbers an order of…

Plasma Physics · Physics 2015-05-13 E. J. Spence , K. Reuter , C. B. Forest

In stars and planets, magnetic fields are believed to originate from the motion of electrically conducting fluids in their interior, through a process known as the dynamo mechanism. In this Letter, an optimization procedure is used to…

Fluid Dynamics · Physics 2015-03-20 Ashley P. Willis

Magnetic fields of low-mass stars and planets are thought to originate from self-excited dynamo action in their convective interiors. Observations reveal a variety of field topologies ranging from large-scale, axial dipole to more…

Solar and Stellar Astrophysics · Physics 2015-06-04 Martin Schrinner , Ludovic Petitdemange , Emmanuel Dormy

Dynamos wherein magnetic field is produced from velocity fluctuations are fundamental to our understanding of several astrophysical and/or laboratory phenomena. Though fluid helicity is known to play a key role in the onset of dynamo…

Plasma Physics · Physics 2023-07-05 Shishir Biswas , Rajaraman Ganesh

We prove the local well-posedness of the 3D free-boundary incompressible elastodynamics with surface tension describing the motion of an elastic medium in a periodic domain with a moving graphical surface. The deformation tensor is assumed…

Analysis of PDEs · Mathematics 2025-01-08 Longhui Xu

Magnetic buoyancy is believed to drive the transport of magnetic flux tubes from the convection zone to the surface of the Sun. The magnetic fields form twisted loop-like structures in the solar atmosphere. In this paper we use helical…

Solar and Stellar Astrophysics · Physics 2011-09-28 Jörn Warnecke , Axel Brandenburg

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

This paper concerns kinematic helical dynamos in a spherical fluid body surrounded by an insulator. In particular, we examine their behaviour in the regime of large magnetic Reynolds number $\Rm$, for which dynamo action is usually…

Earth and Planetary Astrophysics · Physics 2015-05-19 Henrik Latter , David Ivers

The full compressible magnetohydrodynamic system in three-dimensional exterior domains is investigated. For the initial-boundary-value problem of this system with slip boundary condition for the velocity, adiabatic one for the temperature,…

Analysis of PDEs · Mathematics 2022-11-02 Yunkun Chen , Yi Peng , Xue Wang