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Related papers: Convective dynamos in spherical wedge geometry

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A model for a possible variable cosmic object is presented. The model consists of a massive shell surrounding a compact object. The gravitational and self-gravitational forces tend to collapse the shell, but the internal tangential stresses…

General Relativity and Quantum Cosmology · Physics 2009-10-30 Dario Nunez

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

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

Late-type stars rotate differentially owing to anisotropic turbulence in their outer convection zones. The rotation is called solar-like (SL) when the equator rotates fastest and anti-solar (AS) otherwise. Hydrodynamic simulations show a…

Solar and Stellar Astrophysics · Physics 2015-03-25 Bidya Binay Karak , Petri J. Kapyla , Maarit J. Kapyla , Axel Brandenburg , N. Olspert , J. Pelt

To study properties of magneto-hydrodynamic (MHD) convection and resultant dynamo activities in proto-neutron stars (PNSs), we construct a "PNS in a box" simulation model with solving compressible MHD equation coupled with a nuclear…

High Energy Astrophysical Phenomena · Physics 2022-02-21 Youhei Masada , Tomoya Takiwaki , Kei Kotake

In this paper, the gravitational wave generation by a slowly rotating thin-shell wormhole is considered. Since the rotating thin-shell wormhole is assumed to be an axisymmetric rigid body, the rotation axis coincides with the largest…

General Relativity and Quantum Cosmology · Physics 2023-01-10 Sung-Won Kim

We present the first results from three-dimensional spherical shell simulations of magnetic dynamo action realized by turbulent convection penetrating downward into a tachocline of rotational shear. This permits us to assess several…

Astrophysics · Physics 2011-02-11 Matthew Browning , Mark S. Miesch , Allan Sacha Brun , Juri Toomre

Magneto-convection can produce an active region without an initial coherent flux tube. A simulation was performed where uniform, untwisted, horizontal magnetic field of 1 kG strenght was advected into the bottom of a computational domain 48…

Solar and Stellar Astrophysics · Physics 2012-07-19 Robert F. Stein , Åke Nordlund

We present the results of 3--D nonlinear simulations of magnetic dynamo action by core convection within A-type stars of 2 solar masses, at a range of rotation rates. We consider the inner 30% by radius of such stars, with the spherical…

Astrophysics · Physics 2009-11-10 Matthew Browning , Allan Sacha Brun , Juri Toomre

It is shown that vibrated packings of frictional disks self-organize cooperatively onto a rotational-transport state where the long-time angular velocity $\bar\omega_i$ of each disk $i$ is nonzero. Steady rotation is mediated by the…

Statistical Mechanics · Physics 2020-08-26 Cristian Fernando Moukarzel , Gonzalo Peraza-Mues , Osvaldo Carvente

Molecular dynamics simulation has been used to model pattern formation in three-dimensional Rayleigh--Benard convection at the discrete-particle level. Two examples are considered, one in which an almost perfect array of hexagonally-shaped…

Other Condensed Matter · Physics 2009-11-11 D. C. Rapaport

So far, numerical studies of double-diffusive layering in turbulent convective flows have neglected the effects of rotation. We undertake a first step into that direction by investigating how Coriolis forces affect a double-diffusive layer…

Fluid Dynamics · Physics 2014-04-25 Patrick Blies , Friedrich Kupka , Florian Zaussinger , Rainer Hollerbach

We perform Large eddy simulations of turbulent compressible convection in stellar-type convection zones by solving the Navi\'{e}r-Stokes equations in three dimensions. We estimate the extent of penetration into the stable layer above a…

Astrophysics · Physics 2009-06-23 Partha S. Pal , Harinder P. Singh , Kwing L. Chan , M. P. Srivastava

The possibility of non-helical large scale dynamo action is investigated using three-dimensional simulations of global accretion discs as well as idealized local simulations without rotation and only shear. Particular emphasis is placed on…

Astrophysics · Physics 2009-11-06 R. Arlt , A. Brandenburg

We investigate vortex dipoles on surfaces of variable negative curvature, focusing on a catenoid of arbitrary throat radius as a concrete example. We construct the effective dynamical system including mutual and geometric self-interaction…

Mathematical Physics · Physics 2026-03-26 Khushi Banthia , Rickmoy Samanta

We study the connection between spherical wedge and full spherical shell geometries using simple mean-field $\alpha^2$ dynamos. We solve the equations for a one-dimensional time-dependent mean-field dynamo to examine the effects of varying…

Solar and Stellar Astrophysics · Physics 2016-10-05 E. Cole , A. Brandenburg , P. J. Käpylä , M. J. Käpylä

We investigate numerically the self-sustained dynamo action in a spinning sphere whose sense of rotation reverses periodically. This system serves as a simple model of a dynamo in small bodies powered by frequent collisions. It is found…

Geophysics · Physics 2015-06-18 Xing Wei , Rainer Arlt , Andreas Tilgner

We show that three-dimensional spherical-shell condensates respond to rotation by forming two aligned triangular Abrikosov-like vortex lattices on each hemispherical surface. The centrifugal force due to rotation causes an elliptical…

Quantum Gases · Physics 2024-01-05 Angela C White

Bistability and hysteresis of magnetohydrodynamic dipolar dynamos generated by turbulent convection in rotating spherical fluid shells is demonstrated. Hysteresis appears as a transition between two distinct regimes of dipolar dynamos with…

Fluid Dynamics · Physics 2009-04-07 R. D. Simitev , F. H. Busse

Thermal convection is observed in molecular dynamic simulation of a fluidized granular system of nearly elastic hard disks moving under gravity, inside a rectangular box. Boundaries introduce no shearing or time dependence, but the energy…

Statistical Mechanics · Physics 2009-10-31 Rosa Ramirez , Dino Risso , Patricio Cordero