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相关论文: Dynamo action at low magnetic Prandtl numbers: mea…

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The spanwise organization of the flow over a thick airfoil is investigated using surface pressure measurements for a range of angles of attack around maximum lift and high Reynolds numbers (1 Million). Locally strong pressure fluctuations,…

流体动力学 · 物理学 2026-02-04 Badoui Hanna , Bérengère Podvin , Caroline Braud

With a non local shell model of magnetohydrodynamic turbulence we investigate numerically the turbulent dynamo action for low and high magnetic Prandtl numbers ($Pm$). The results obtained in the kinematic regime and along the way to dynamo…

天体物理学 · 物理学 2009-11-13 Rodion Stepanov , Franck Plunian

It is numerically demonstrated by means of a magnetohydrodynamics code that a short Taylor-Couette setup with a body force can sustain dynamo action. The magnetic threshold is comparable to what is usually obtained in spherical geometries.…

数值分析 · 数学 2015-06-04 C. Nore , J. -L. Guermond , R. Laguerre , J. Leorat , F. Luddens

Dynamos driven by rotating convection in the plane layer geometry are investigated numerically for a range of Ekman number ($E$), magnetic Prandtl number ($Pm$) and Rayleigh number ($Ra$). The primary purpose of the investigation is to…

流体动力学 · 物理学 2022-11-23 Ming Yan , Michael A. Calkins

This paper concerns kinematic helical dynamos in a spherical fluid body surrounded by an insulator. In particular, we examine their behaviour in the regime of large magnetic Reynolds number $\Rm$, for which dynamo action is usually…

地球与行星天体物理 · 物理学 2015-05-19 Henrik Latter , David Ivers

The turbulent dynamo may explain the origin of cosmic magnetism. While the exponential amplification of magnetic fields has been studied for incompressible gases, little is known about dynamo action in highly-compressible, supersonic…

星系天体物理 · 物理学 2014-12-05 Christoph Federrath , Jennifer Schober , Stefano Bovino , Dominik R. G. Schleicher

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…

等离子体物理 · 物理学 2015-05-13 Gregory L. Eyink , Antonio F. Neto

We consider the generation of magnetic activity --- dynamo waves --- in the astrophysical limit of very large magnetic Reynolds number. We consider kinematic dynamo action for a system consisting of helical flow and large-scale shear. We…

太阳与恒星天体物理 · 物理学 2015-06-19 Fausto Cattaneo , Steven Tobias

A new kind of dynamo utilizing flowing laboratory plasmas has been identified. Conversion of plasma kinetic energy to magnetic energy is verified numerically by kinematic dynamo simulations for magnetic Reynolds numbers above 210. As…

天体物理学 · 物理学 2009-11-07 Zhehui Wang , Vladimir I. Pariev , Cris W. Barnes , Daniel C. Barnes

(abidged) Context: Stellar convection zones are characterized by vigorous high-Reynolds number turbulence at low Prandtl numbers. Aims: We study the dynamo and differential rotation regimes at varying levels of viscous, thermal, and…

太阳与恒星天体物理 · 物理学 2017-02-22 P. J. Käpylä , M. J. Käpylä , N. Olspert , J. Warnecke , A. Brandenburg

The energy method, also known as the Reynolds-Orr equation, is widely utilized in predicting the unconditional stability threshold of shear flows owing to the zero contribution of nonlinear terms to the time derivative of perturbation…

流体动力学 · 物理学 2023-11-01 Péter Tamás Nagy

We study the dynamo instability for a Kazantsev-Kraichnan flow with three velocity components that depends only on two-dimensions u = (u(x, y, t), v(x, y, t), w(x, y, t)) often referred to as 2.5 dimensional (2.5D) flow. Within the…

流体动力学 · 物理学 2016-11-03 K. Seshasayanan , A. Alexakis

We consider a test problem for Navier-Stokes solvers based on the flow around a cylinder that exhibits chaotic behavior, to examine the behavior of various numerical methods. We choose a range of Reynolds numbers for which the flow is…

数值分析 · 数学 2024-08-19 Henry von Wahl , L. Ridgway Scott

Turbulent motions in a fluid relax at a certain rate once stirring has stopped. The role of the most basic parameter in fluid mechanics, the Reynolds number, in setting the relaxation rate is not generally known. This paper concerns the…

流体动力学 · 物理学 2015-06-22 Michael Sinhuber , Eberhard Bodenschatz , Gregory P. Bewley

We numerically investigate the efficiency of a spherical Couette flow at generating a self-sustained magnetic field. No dynamo action occurs for axisymmetric flow while we always found a dynamo when non-axisymmetric hydrodynamical…

地球物理 · 物理学 2020-07-17 Céline Guervilly , Philippe Cardin

We present numerical investigations into three principal properties of the small-scale dynamo in stably stratified turbulence: the onset criterion, the growth rate, and the nature of the magnetic field anisotropy in the kinematic regime.…

流体动力学 · 物理学 2021-02-04 Valentin Skoutnev , Jonathan Squire , Amitava Bhattacharjee

We are investigating numerically the non-linear behavior of a space-periodic MHD system with ABC forcing. Most computations are performed for magnetic Reynolds numbers increasing from 0 to 60 and a fixed kinematic Reynolds number, small…

流体动力学 · 物理学 2007-05-23 Olga M. Podvigina

The growth rate of the dynamo instability as a function of the magnetic Reynolds number Rm is investigated by means of numerical simulations for the family of the ABC flows and for 2 different forcing scales. For the ABC flows that are…

流体动力学 · 物理学 2015-05-28 Alexandros Alexakis

We analyze the data stemming from a forced incompressible hydrodynamic simulation on a grid of 2048^3 regularly spaced points, with a Taylor Reynolds number of Re~1300. The forcing is given by the Taylor-Green flow, which shares…

流体动力学 · 物理学 2009-11-13 P. D. Mininni , A. Alexakis , A. Pouquet

Elasto-inertial turbulence is a new state of turbulence found in flows with polymer additives . The dynamics of turbulence generated and controlled by such additives is investigated from the perspective of the coupling between polymer…

流体动力学 · 物理学 2015-06-12 Yves Dubief , Vincent E. Terrapon , Julio Soria