English
Related papers

Related papers: Nonhelical turbulent dynamos: shocks and shear

200 papers

This paper investigates the statistical properties of isothermal turbulence in both the subsonic and supersonic regimes. The focus is on the influence of the Mach number ($Ma$) and the Reynolds number ($Re$) on both the space-local and…

Fluid Dynamics · Physics 2025-10-16 F. Thiesset , C. Federrath

We numerically examine dynamo action generated by a flow of an electrically conducting fluid in a precessing cylindrical cavity. We compare a simplified kinematic approach based on the solution of the magnetic induction equation with a…

Fluid Dynamics · Physics 2025-04-07 André Giesecke , Mike Wilbert , Ján Šimkanin , Rainer Grauer , Frank Stefani

Direct numerical simulation is used to investigate the decay exponent of isotropic homogeneous turbulence over a range of Reynolds numbers sufficient to display both high and low Re number decay behavior. The initial turbulence is generated…

Fluid Dynamics · Physics 2010-07-29 J. Blair Perot

The dynamics of convecting fluids in rotating spherical shells is governed at Prandtl numbers of the order unity by the interaction between differential rotation and roll-like convection eddies. While the differential rotation is driven by…

Fluid Dynamics · Physics 2009-05-25 F. H. Busse , R. D. Simitev

Nonlinear gyrokinetic simulations have been conducted to investigate turbulent transport in tokamak plasmas with rotational shear. At sufficiently large flow shears, linear instabilities are suppressed, but transiently growing modes drive…

Plasma Physics · Physics 2015-05-19 M. Barnes , F. I. Parra , E. G. Highcock , A. A. Schekochihin , S. C. Cowley , C. M. Roach

Turbulence -- ubiquitous in nature and engineering alike [1-5] -- is traditionally viewed as an intrinsically inertial phenomenon, emerging only when the Reynolds number (Re), which quantifies the ratio of inertial to dissipative forces…

Fluid Dynamics · Physics 2025-11-11 Ziyue Yu , Xinyu Si , Lei Fang

A subcritical transition to turbulence in magnetized Keplerian shear flows is investigated using a statistical approach. Three-dimensional numerical simulations of the shearing box equations with zero net magnetic flux are employed to…

Earth and Planetary Astrophysics · Physics 2015-05-19 Erico L. Rempel , Geoffroy Lesur , Michael R. E. Proctor

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

We present results from numerical simulations of nonlinear MHD dynamo action produced by three-dimensional flows that become turbulent for high values of the fluid Reynolds number. The magnitude of the forcing function driving the flow is…

Astrophysics · Physics 2009-11-07 Vasilis Archontis , Bertil Dorch , Aake Nordlund

We revisit the problem of how energy transfer through the turbulent cascade operates in compressible hydrodynamic turbulence. In general, there is no conservative compressible cascade since the kinetic and internal energy reservoirs can…

Fluid Dynamics · Physics 2019-12-09 Wolfram Schmidt , Philipp Grete

We consider kinematic dynamo action in rapidly rotating Boussinesq convection just above onset. The velocity is constrained to have either a square or a hexagonal pattern. For the square pattern, large-scale dynamo action is observed at…

Fluid Dynamics · Physics 2015-06-17 B. Favier , M. R. E. Proctor

We investigate three-dimensional magnetohydrodynamics turbulence in the presence of both a large-scale velocity and non-uniform magnetic field. By assuming a turbulence driven by an external forcing with both helical and non-helical…

Fluid Dynamics · Physics 2015-05-13 Nicolas Leprovost , Eun-Jin Kim

We study the dynamo instability driven by a turbulent two dimensional flow with three components of the form (u(x, y, t), v(x, y, t), w(x, y, t)) sometimes referred to as a 2.5 dimensional flow. This type of flows provides an approximation…

Fluid Dynamics · Physics 2016-08-24 K. Seshasayanan , A. Alexakis

A three-dimensional direct numerical simulation (3D DNS) is performed to describe the turbulent flow in an enclosed rotor-stator cavity characterized by a large aspect ratio $G=(b-a)/h=18.32$ and a small radius ratio $a/b=0.15$ ($a$ and $b$…

Classical Physics · Physics 2016-08-16 Sébastien Poncet , Anthony Randriamampianina

A plane-shear flow in a fluid with forced turbulence is considered. If the fluid is electrically-conducting then a mean electromotive force (EMF) results even without basic rotation and the magnetic diffusivity becomes a highly anisotropic…

Astrophysics · Physics 2009-11-11 G. Ruediger , L. L. Kitchatinov

Turbulence in a conducting plasma can amplify seed magnetic fields in what is known as the turbulent, or small-scale, dynamo. The associated growth rate and emergent magnetic-field geometry depend sensitively on the material properties of…

High Energy Astrophysical Phenomena · Physics 2022-10-17 Alisa K. Galishnikova , Matthew W. Kunz , Alexander A. Schekochihin

(Abridged) The small-scale dynamo may play a substantial role in magnetizing the Universe under a large range of conditions, including subsonic turbulence at low Mach numbers, highly supersonic turbulence at high Mach numbers and a large…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 Dominik R. G. Schleicher , Jennifer Schober , Christoph Federrath , Stefano Bovino , Wolfram Schmidt

Numerical simulations of turbulent round jets, using explicit-filtered LES technique, are performed, for three different Reynolds numbers(Re = 3600, 88000, 400000), to understand the Reynolds number effect on subsonic jets with Mach number…

Fluid Dynamics · Physics 2017-11-22 Ramanathan Varadharajan

Direct numerical simulation of a turbulent channel flow with heat transfer was performed at very low Reynolds numbers. Two different thermal boundary conditions were studied, and temperature was considered as a passive scalar. The…

Fluid Dynamics · Physics 2014-06-05 Takahiro Tsukahara , Hiroshi Kawamura

Turbulence is ubiquitous in astrophysical fluids such as the interstellar medium (ISM) and the intracluster medium (ICM). In turbulence studies, it is customary to assume that fluid is driven on a single scale. However, in astrophysical…

Astrophysics of Galaxies · Physics 2015-06-18 Hyunju Yoo , Jungyeon Cho