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Related papers: The role of curvature and stretching in dynamo pla…

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We study the kinematic dynamo equation on the three-torus and provide a rigorous proof of fast dynamo action for a time-periodic, divergence-free, Lipschitz velocity field. Our construction is based on a stretch-fold-shear mechanism…

Analysis of PDEs · Mathematics 2026-05-20 Michele Coti Zelati , Massimo Sorella , David Villringer

The kinematic dynamo problem is investigated for the flow of a conducting fluid in a cylindrical, periodic tube with conducting walls. The methods used are an eigenvalue analysis of the steady regime, and the three-dimensional solution of…

Astrophysics · Physics 2009-11-07 Wolfgang Dobler , Peter Frick , Rodion Stepanov

The paper defines and discusses the concept of hidden drifts in two-dimensional turbulence. These are ordered components of the trajectories that average to zero and do not produce direct transport. Their effects appear in the evolution of…

Plasma Physics · Physics 2019-01-30 Madalina Vlad , Florin Spineanu

Astrophysical and geophysical fluids commonly generate organized magnetic fields, despite having enormous magnetic Reynolds numbers $\rm{Rm}$ and abundant small-scale turbulence. Flow-induced dynamo action produces these fields, with the…

Heisenberg spin equation equivalence to nonlinear Schr\"{o}dinger equation recently demonstrated by Rogers and Schief, is applied to the investigation of vortex filaments in magnetohydrodynamics (MHD) dynamos. The use of…

Plasma Physics · Physics 2007-05-23 L. C. Garcia de Andrade

Assuming the stability of soliton surfaces of vanishing Ricci sectional curvature of soliton metric in the nonholonomic frame, we find a solution for the metric in the approximation of weak constant torsion curves with constant Frenet…

Fluid Dynamics · Physics 2007-08-15 Garcia de Andrade

We supplement the mean field dynamo growth equation with the total magnetic helicity evolution equation. This provides an explicitly time dependent model for alpha quenching in dynamo theory. For dynamos without shear, this approach…

Astrophysics · Physics 2009-11-07 Eric G. Blackman , Axel Brandenburg

It is shown that C-flows in Riemannian three-dimensional compact manifold can be naturally considered as generalized dynamo Arnold's metric in compact manifolds, the so-called cat map dynamo. The generalized solution of self-induction…

Mathematical Physics · Physics 2008-03-06 L Garcia de Andrade

In this paper we investigate the idea of Hanasz & Lesch 1993 that the galactic dynamo effect is due to the Parker instability of magnetic flux tubes. In addition to the former approach, we take into account more general physical conditions…

Astrophysics · Physics 2008-02-03 M. Hanasz , H. Lesch

We investigate numerically kinematic dynamos driven by flow of electrically conducting fluid in the shell between two concentric differentially rotating spheres, a configuration normally referred to as spherical Couette flow. We compare…

Earth and Planetary Astrophysics · Physics 2012-08-07 Xing Wei , Andrew Jackson , Rainer Hollerbach

Motivated by problems arising in tear film dynamics, we present a model for the extensional flow of thin sheets of nematic liquid crystal. The rod-like molecules of these substances impart an elastic contribution to its response. We rescale…

Fluid Dynamics · Physics 2023-06-28 M. J. Taranchuk , L. J. Cummings , T. A. Driscoll , R. J. Braun

A nonmodal kinetic theory of the stability of the two-dimensional compressed-sheared mesoscale plasma flows, generated by the radially inhomogeneous electrostatic ion cyclotron parametric microturbulence in the pedestal plasma with a…

Plasma Physics · Physics 2023-05-24 V. S. Mikhailenko , V. V. Mikhailenko , Hae June Lee

The weak collisionality typical of turbulence in many diffuse astrophysical plasmas invalidates an MHD description of the turbulent dynamics, motivating the development of a more comprehensive theory of kinetic turbulence. In particular, a…

Solar and Stellar Astrophysics · Physics 2015-02-17 Gregory G. Howes

We present a simple semi-analytical model of nonlinear, mean-field galactic dynamos and use it to study the effects of various magnetic helicity fluxes. The dynamo equations are reduced using the `no-$z$' approximation to a nonlinear system…

Astrophysics · Physics 2008-11-26 Sharanya Sur , Anvar Shukurov , Kandaswamy Subramanian

We analyze the creeping flow generated by a spherical particle moving through a viscous fluid with nematic directional order, in which momentum diffusivity is anisotropic and which opposes resistance to bending. Specifically, we provide…

Fluid Dynamics · Physics 2013-09-11 Manuel Gómez-González , Juan C. del Álamo

The particle and momentum balance equations can be solved on concentric circular flux surfaces to determine the effective viscous drag present in a magnetized tokamak plasma in the low aspect ratio limit. An analysis is developed utilizing…

Plasma Physics · Physics 2007-10-16 Robert W. Johnson

Although turbulence has been conjectured to be important for magnetic reconnection, still very little is known about its role in collisionless plasmas. Previous attempts to quantify the effect of turbulence on reconnection usually…

Plasma Physics · Physics 2018-11-07 P. A. Muñoz , J. Büchner

Kinematic dynamo theory is presented here for turbulent conductive fluids. We describe how inhomogeneous magnetic fluctuations are generated below the viscous scale of turbulence where the spatial smoothness of the velocity permits a…

chao-dyn · Physics 2009-10-31 M. Chertkov , G. Falkovich , I. Kolokolov , M. Vergassola

This paper, Part I of a series, describes a kinematic framework for the theory of a Dense Plasma Focus which is very similar to the GV model in spirit but which differs in its scope in four respects. First, the GV model derives most of its…

Plasma Physics · Physics 2022-12-01 S K H Auluck

Magnetic curvature effects, investigated by Barrow and Tsagas (BT) [Phys Rev D \textbf{77},(2008)],as a mechanism for magnetic field decay in open Friedmann universes (${\Lambda}<0$), are applied to dynamo geometric Ricci flows in 3D curved…

General Relativity and Quantum Cosmology · Physics 2009-05-14 Garcia de Andrade