English
Related papers

Related papers: Angular momentum transport in convectively unstabl…

200 papers

To study the Reynolds stresses which describe turbulent momentum transport from turbulence affected by large-scale shear and rotation. Three-dimensional numerical simulations are used to study turbulent transport under the influences of…

Solar and Stellar Astrophysics · Physics 2009-11-19 J. E. Snellman , P. J. Käpylä , M. J. Korpi , A. J. Liljeström

Context: Rotating anisotropic convection generates differential rotation in stellar convection zones. Aims: The main aim is to compute the non-diffusive contribution ($\Lambda$ effect) to angular momentum transport, described by Reynolds…

Solar and Stellar Astrophysics · Physics 2026-03-11 P. J. Käpylä

Small levels of turbulence can be present in stellar radiative interiors due to, e.g., instability of rotational shear. In this paper we estimate turbulent transport coefficients for stably stratified rotating stellar radiation zones.…

Solar and Stellar Astrophysics · Physics 2012-05-23 L. L. Kitchatinov , A. Brandenburg

We present angular momentum transport (torque) measurements in two recent experimental studies of the turbulent flow between independently rotating cylinders. In addition to these studies, we reanalyze prior torque measurements to expand…

Fluid Dynamics · Physics 2012-11-12 M. S. Paoletti , Dennis P. M. van Gils , B. Dubrulle , Chao Sun , Detlef Lohse , D. P. Lathrop

Homogeneous anisotropic turbulence simulations are used to determine off-diagonal components of the Reynolds stress tensor and its parameterization in terms of turbulent viscosity and Lambda-effect. The turbulence is forced in an…

Astrophysics · Physics 2011-11-10 P. J. Käpylä , A. Brandenburg

We provide a consistent theory of turbulence in the presence of shear and rotation. Starting from a quasi-linear equation for the fluctuating fields, we derive turbulence amplitude and turbulent transport coefficients, taking into account…

Fluid Dynamics · Physics 2009-11-13 Nicolas Leprovost , Eun-Jin Kim

The stability of conducting Taylor-Couette flows under the presence of toroidal magnetic background fields is considered. For strong enough magnetic amplitudes such magnetohydrodynamic flows are unstable against nonaxisymmetric…

Plasma Physics · Physics 2020-01-08 G. Rüdiger , M. Schultz

Various approaches to estimate turbulent transport coefficients from numerical simulations of hydromagnetic turbulence are discussed. A quantitative comparison between the averaged magnetic field obtained from a specific three-dimensional…

Astrophysics · Physics 2009-11-07 Axel Brandenburg , Dmitry Sokoloff

The velocity fluctuations in a spherical shell arising from sinusoidal perturbations of a Keplerian shear flow with a free amplitude parameter \epsilon are studied numerically by means of fully 3D nonlinear simulations. The investigations…

Astrophysics · Physics 2009-11-06 G. Rudiger , A. Drecker

We report a laboratory study of the transport of angular momentum by a turbulent flow of an electrically conducting fluid confined in a thin disk. When the electromagnetic force applied to the liquid metal is large enough, the corresponding…

Fluid Dynamics · Physics 2022-08-31 Marlone Vernet , Stephan Fauve , Christophe Gissinger

Aims: We determine the components of the $\Lambda$-effect tensor that quantifies the contributions to the turbulent momentum transport even for uniform rotation. Methods: Three-dimensional numerical simulations are used to study turbulent…

Astrophysics · Physics 2008-08-22 P. J. Käpylä , A. Brandenburg

The turbulent diffusion tensor describing the evolution of the mean concentration of a passive scalar is investigated for non-helically forced turbulence in the presence of rotation or a magnetic field. With rotation, the Coriolis force…

Solar and Stellar Astrophysics · Physics 2009-05-09 Axel Brandenburg , Andreas Svedin , Geoffrey M. Vasil

(abridged) Aims: To study turbulent transport coefficients that describe the evolution of large-scale magnetic fields in turbulent convection. Methods: We use the test field method together with 3D numerical simulations of turbulent…

Astrophysics · Physics 2009-07-29 P. J. Käpylä , M. J. Korpi , A. Brandenburg

Hydrodynamic unstratified keplerian flows are known to be linearly stable at all Reynolds numbers, but may nevertheless become turbulent through nonlinear mechanisms. However, in the last ten years, conflicting points of view have appeared…

Astrophysics · Physics 2009-11-11 G. Lesur , P-Y. Longaretti

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

We study the dependence of turbulent transport coefficients, such as the components of the $\alpha$ tensor ($\alpha_{ij}$) and the turbulent magnetic diffusivity tensor ($\eta_{ij}$), on shear and magnetic Reynolds number in the presence of…

Astrophysics · Physics 2009-03-03 Dhrubaditya Mitra , Petri J. Käpylä , Reza Tavakol , Axel Brandenburg

We demonstrate with a nonlinear MHD code that angular momentum can be transported due to the magnetic instability of toroidal fields under the influence of differential rotation, and that the resulting effective viscosity may be high enough…

Solar and Stellar Astrophysics · Physics 2015-06-19 G. Ruediger , M. Gellert , F. Spada , I. Tereshin

We study the effect of rotation on sheared turbulence, due to differential rotation. By solving quasi-linear equations for the fluctuating fields, we derive turbulence amplitude and turbulent transport coefficients, taking into account the…

Astrophysics · Physics 2008-11-26 Nicolas Leprovost , Eun-Jin Kim

We experimentally and numerically investigate the angular momentum transport in turbulent Taylor-Couette flow for independently rotating cylinders at a small radius ratio of $\eta=0.357$ for various shear Reynolds numbers ($4.5\times 10^3…

Recently, the vertical shear instability (VSI) has become an attractive purely hydrodynamic candidate for the anomalous angular momentum transport required for weakly ionized accretion disks. In direct three-dimensional numerical…

Solar and Stellar Astrophysics · Physics 2017-03-08 Moritz H. R. Stoll , Giovanni Picogna , Wilhelm Kley
‹ Prev 1 2 3 10 Next ›