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Related papers: Shear dynamo problem: Quasilinear kinematic theory

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We study a complex Ginzburg-Landau (GL) type model related to fluid instabilities in the boundary of magnetized toroidal plasmas (called edge-localized modes) with a prescribed shear flow on the Neumann boundary condition. We obtain the…

Plasma Physics · Physics 2017-06-27 Youngmin Oh , Gunsu S. Yun , Hyung Ju Hwang

The effects of uniform horizontal shear on a stably stratified layer of gas is studied. The system is initially destabilized by a magnetically buoyant flux tube pointing in the cross-stream direction. The shear amplifies the initial field…

Solar and Stellar Astrophysics · Physics 2014-11-20 Violaine Vermersch , Axel Brandenburg

In this work we numerically demonstrate both significant transient (i.e. non-modal) linear amplification and sustained nonlinear turbulence in a kinetic plasma system with no unstable eigenmodes. The particular system considered is an…

Plasma Physics · Physics 2015-07-22 Matt Landreman , Gabriel G. Plunk , William Dorland

The effect of strong shear flow on highly fluctuating lamellar systems stabilized by intermembrane collisions via the Helfrich interaction is studied. Advection enters the microscopic equation of motion for a single membrane via a…

Soft Condensed Matter · Physics 2009-11-07 Simon W. Marlow , Peter D. Olmsted

Small-scale turbulent dynamo is responsible for the amplification of magnetic fields on scales smaller than the driving scale of turbulence in diverse astrophysical media. Most earlier dynamo theories concern the kinematic regime and…

Astrophysics of Galaxies · Physics 2021-06-25 Siyao Xu , Alex Lazarian

To advance our understanding of the magnetohydrodynamic (MHD) processes in liquid metals, in this paper we propose an approach combining the classical methods in the dynamo theory based on numerical simulations of the partial differential…

Fluid Dynamics · Physics 2025-10-16 Francisco Stefano de Almeida , Roman Chertovskih , Sílvio Gama , Rui Gonçalves

Recently, Silvers, Vasil, Brummell, & Proctor (2009), using numerical simulations, confirmed the existence of a double diffusive magnetic buoyancy instability of a layer of horizontal magnetic field produced by the interaction of a shear…

Solar and Stellar Astrophysics · Physics 2015-05-30 Lara J. Silvers , Geoffrey M. Vasil , Nicholas H. Brummell , Michael R. E. Proctor

We have extended our previous mean-field galactic dynamo model which included algebraic and dynamic alpha nonlinearities (Kleeorin et al., A&A, v. 387, 453, 2002), to include also a quenching of turbulent diffusivity. We readily obtain…

Astrophysics · Physics 2014-10-13 N. Kleeorin , D. Moss , I. Rogachevskii , D. Sokoloff

We present nonlinear mean-field alpha-Omega dynamo simulations in spherical geometry with simplified profiles of kinematic alpha effect and shear. We take magnetic helicity evolution into account by solving a dynamical equation for the…

Solar and Stellar Astrophysics · Physics 2010-12-10 Gustavo Guerrero , Piyali Chatterjee , Axel Brandenburg

The Kelvin-Helmholtz (KH) instability of a shear layer with an initially-uniform magnetic field in the direction of flow is studied in the framework of 2D incompressible magnetohydrodynamics with finite resistivity and viscosity using…

Plasma Physics · Physics 2021-03-15 A. E. Fraser , P. W. Terry , E. G. Zweibel , M. J. Pueschel , J. M. Schroeder

Using a one-dimensional $\alpha\omega$-dynamo model appropriate to galaxies, we study the possibility of dynamo action driven by a stochastic alpha effect and shear. To determine the field evolution, one needs to examine a large number of…

Astrophysics · Physics 2009-11-13 Sharanya Sur , Kandaswamy Subramanian

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

When scale separation in space and time is poor, the alpha effect and turbulent diffusivity have to be replaced by integral kernels. Earlier work in computing these kernels using the test-field method is now generalized to the case in which…

Solar and Stellar Astrophysics · Physics 2012-01-11 M. Rheinhardt , A. Brandenburg

Within the framework of shallow-water magnetohydrodynamics, we investigate the linear instability of horizontal shear flows, influenced by an aligned magnetic field and stratification. Various classical instability results, such as…

Fluid Dynamics · Physics 2016-01-15 Julian Mak , Stephen D. Griffiths , D. W. Hughes

Nonlinearities in constitutive equations of extended objects in shear flow lead to novel phenomena, {\it e.g.} "rheochaos" in solutions of wormlike micelles and "elastic turbulence" in polymer solutions. Since both phenomena involve…

Soft Condensed Matter · Physics 2019-08-20 Rituparno Mandal , Buddhapriya Chakrabarti , Debarshini Chakraborti , Chandan Dasgupta

Using the magnetohydrodynamic (MHD) description, we develop a nonlinear dynamo model that couples the evolution of the large scale magnetic field with turbulent dynamics of the plasma at small scale by electromotive force (e.m.f.) in the…

Earth and Planetary Astrophysics · Physics 2011-09-29 Giuseppina Nigro , Pierlugi Veltri

We consider the generation of magnetic field by a turbulent flow. For the linear induction equation (i.e. the kinematic dynamo problem), we show that the statistical moments of the magnetic field display multiscaling and in particular…

Fluid Dynamics · Physics 2018-09-12 Kannabiran Seshasayanan , Francois Petrelis

We theoretically study the conformational and dynamical properties of semiflexible active polar ring polymers under linear shear flow. A ring is described as a continuous Gaussian polymer with a tangential active force of a constant density…

Soft Condensed Matter · Physics 2024-07-04 Roland G. Winkler , Sunil P. Singh

A joint effect of the density-stratified turbulence (or inhomogeneous turbulence) and a large-scale shear for arbitrary Mach numbers results in the $\alpha$ effect and mean-field dynamo action. These effects also produce the effective…

Astrophysics of Galaxies · Physics 2026-03-19 Igor Rogachevskii , Nathan Kleeorin

We find and investigate via numerical simulations self-sustained two-dimensional turbulence in a magnetohydrodynamic flow with a maximally simple configuration: plane, noninflectional (with a constant shear of velocity) and threaded by a…

Plasma Physics · Physics 2014-10-01 G. R. Mamatsashvili , D. Z. Gogichaishvili , G. D. Chagelishvili , W. Horton