English
Related papers

Related papers: Shear dynamo problem: Quasilinear kinematic theory

200 papers

We present a numerical study of turbulence and dynamo action in stratified shearing boxes with zero mean magnetic flux. We assume that the fluid obeys the perfect gas law and has finite (constant) thermal diffusivity. The calculations begin…

High Energy Astrophysical Phenomena · Physics 2015-06-11 G. Bodo , F. Cattaneo , A. Mignone , P. Rossi

Simulations of stochastically forced shear-flow turbulence in a shearing-periodic domain are used to study the spontaneous generation of large-scale flow patterns in the direction perpendicular to the plane of the shear. Based on an…

Astrophysics · Physics 2009-01-09 Petri J. Käpylä , Dhrubaditya Mitra , Axel Brandenburg

We investigate the nonlinear dynamics of turbulent shear flows, with and without rotation, in the context of a simple but physically motivated closure of the equation governing the evolution of the Reynolds stress tensor. We show that the…

Astrophysics · Physics 2009-11-10 Pascale Garaud , Gordon I. Ogilvie

Nonlinear tranlational symmetric equilibria with up to quartic flux terms in the free functions, reversed magnetic shear and sheared flow are constructed in two ways: i) quasianalytically by an ansatz which reduces the pertinent generalized…

Plasma Physics · Physics 2019-02-20 Ap Kuiroukidis , G. N. Throumoulopoulos

Global and semi-global convective dynamo simulations of solar-like stars are known to show a transition from an anti-solar (fast poles, slow equator) to solar-like (fast equator, slow poles) differential rotation (DR) for increasing…

Solar and Stellar Astrophysics · Physics 2019-11-25 M. Viviani , M. J. Käpylä , J. Warnecke , P. J. Käpylä , M. Rheinhardt

We investigate the Lagrangian mechanism of the kinematic ``fluctuation'' magnetic dynamo in turbulent plasma flow at small magnetic Prandtl numbers. The combined effect of turbulent advection and plasma resistivity is to carry infinitely…

Plasma Physics · Physics 2015-05-13 Gregory L. Eyink , Antonio F. Neto

We derive a new shell model of magnetohydrodynamic (MHD) turbulence in which the energy transfers are not necessary local. Like the original MHD equations, the model conserves the total energy, magnetic helicity, cross-helicity and volume…

Fluid Dynamics · Physics 2009-09-29 F. Plunian , R. Stepanov

We examine how perturbed shear flows evolve in two-dimensional, incompressible, inviscid hydrodynamical fluids, with the ultimate goal of understanding the dynamics of accretion disks. To linear order, vorticity waves are swung around by…

Astrophysics · Physics 2009-11-13 Yoram Lithwick

The magnetorotational instability (MRI) is an important process in sufficiently ionized accretion disks, as it can create turbulence that acts as an effective viscosity, mediating angular momentum transport. Due to its local nature, it is…

Earth and Planetary Astrophysics · Physics 2023-09-28 Oliver Zier , Volker Springel

Motivated by recent experimental and numerical results, a simple unifying picture of intermittency in turbulent shear flows is suggested. Integral Structure Functions (ISF), taking into account explicitly the shear intensity, are introduced…

Chaotic Dynamics · Physics 2007-05-23 F. Toschi , E. Leveque , G. Ruiz-Chavarria

The nonequilibrium structural and dynamical properties of semiflexible active polar polymers subject to linear flow are studied by numerical simulations. Filaments are confined in two dimensions and immersed in a fluid described by the…

Soft Condensed Matter · Physics 2026-04-23 A. Lamura , R. G. Winkler

We reveal and analyze an efficient magnetic dynamo action due to precession-driven hydrodynamic turbulence in the local model of a precessional flow, focusing on the kinematic stage of this dynamo. The growth rate of magnetic field…

Fluid Dynamics · Physics 2024-05-08 V. Kumar , F. Pizzi , G. Mamatsashvili , A. Giesecke , F. Stefani , A. J. Barker

Rotating shear flows, when angular momentum increases and angular velocity decreases as functions of radiation coordinate, are hydrodynamically stable under linear perturbation. The Keplerian flow is an example of such systems which appears…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Banibrata Mukhopadhyay , Ranchu Mathew , Soumyendu Raha

This article presents a calculation of the mean electromotive force arising from general small-scale magnetohydrodynamical turbulence, within the framework of the second-order correlation approximation. With the goal of improving…

High Energy Astrophysical Phenomena · Physics 2015-11-23 Jonathan Squire , Amitava Bhattacharjee

The non-linear response of entangled polymers to shear flow is complicated. Its current understanding is framed mainly as a rheological description in terms of the complex viscosity. However, the full picture requires an assessment of the…

Computational Physics · Physics 2018-08-21 Airidas Korolkovas , Philipp Gutfreund , Max Wolff

The emergence of large-scale magnetic fields observed in the diffuse interstellar medium is explained by a turbulent dynamo. The underlying transport coefficients have previously been extracted from numerical simulations. So far, this was…

Astrophysics of Galaxies · Physics 2015-06-11 Oliver Gressel , Abhijit Bendre , Detlef Elstner

The electrostatic shear-flow-driven ion cyclotron instability of magnetic field aligned sheared plasma flow is investigated analytically. It is shown that the shear-flow-driven electrostatic ion cyclotron instability can be considered as a…

Plasma Physics · Physics 2011-01-18 D. V. Chibisov , V. S. Mikhailenko , K. N. Stepanov

A conducting Taylor-Couette flow with quasi-Keplerian rotation law containing a toroidal magnetic field serves as a mean-field dynamo model of the Tayler-Spruit-type. The flows are unstable against nonaxisymmetric perturbations which form…

Solar and Stellar Astrophysics · Physics 2020-02-12 G. Rüdiger , M. Schultz

The possibility of explaining shear flow dynamos by a magnetic shear-current (MSC) effect is examined via numerical simulations. Our primary diagnostics is the determination of the turbulent magnetic diffusivity tensor $\boldsymbol{\eta}$.…

We employ a variety of numerical simulations in the local shearing box system to investigate in greater depth the local hydrodynamic stability of Keplerian differential rotation. In particular we explore the relationship of Keplerian shear…

Astrophysics · Physics 2009-10-31 John F. Hawley , Steven A. Balbus , Wayne F. Winters
‹ Prev 1 8 9 10 Next ›