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Related papers: Rotational effects on the small-scale dynamo

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Motivated by the large effect of turbulent drag reduction by minute concentrations of polymers we study the effects of a weakly space-dependent viscosity on the stability of hydrodynamic flows. In a recent Letter [Phys. Rev. Lett. {\bf 87},…

Chaotic Dynamics · Physics 2009-11-07 Rama Govindarajan , Victor S. L'vov , Itamar Procaccia

An addition of polymers can significantly reduce drag in wall-bounded turbulent flows, such as pipes or channels. This phenomenon is accompanied by a noticeable modification of the mean velocity profile. Starting from the premise that…

Fluid Dynamics · Physics 2025-08-22 Wouter J. T. Bos , Xuan Shao , Tong Wu , Le Fang

Experimental measurements of domain wall propagation are typically interpreted by comparison to reduced models that ignore both the effects of disorder and the internal dynamics of the domain wall structure. Using micromagnetic simulations,…

Mesoscale and Nanoscale Physics · Physics 2010-05-27 Hongki Min , Robert D. McMichael , Michael J. Donahue , Jacques Miltat , M. D. Stiles

The dynamics of inertial particles in turbulence is modelled and investigated by means of direct numerical simulation of an axisymmetrically expanding homogeneous turbulent strained flow. This flow can mimic the dynamics of particles close…

Fluid Dynamics · Physics 2023-07-19 Chung-min Lee , Ármann Gylfason , Prasad Perlekar , Federico Toschi

The expansion of the rotating fluid will change the vorticity and rotational speed of the expanding region. In turbulent thermal convection, this microscopic effect is preserved. Tracking the fluid micelles shows that the average vorticity…

Solar and Stellar Astrophysics · Physics 2023-01-03 Haibin Chen , Rong Wu

Nonhelical shear dynamos are studied with a particular focus on the possibility of coherent dynamo action. The primary results -- serving as a follow up to the results of Squire & Bhattacharjee [arXiv:1506.04109 (2015)] -- pertain to the…

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

The magnetic field in stellar radiation zones can play an important role in phenomena such as mixing, angular momentum transport, etc. We study the effect of rotation on the stability of a predominantly toroidal magnetic field in the…

Solar and Stellar Astrophysics · Physics 2015-06-15 Alfio Bonanno , Vadim Urpin

We investigate experimentally the influence of a background rotation on the energy transfers in decaying grid turbulence. The anisotropic energy flux density, ${\bf F} ({\bf r}) = < \delta {\bf u}\,(\delta {\bf u})^2 >$, where $\delta {\bf…

Fluid Dynamics · Physics 2012-05-22 Cyril Lamriben , Pierre-Philippe Cortet , Frédéric Moisy

What is the turbulent drag force experienced by an object moving in a rotating fluid? This open and fundamental question can be addressed by measuring the torque needed to drive an impeller at constant angular velocity $\omega$ in a water…

While present standard model of cosmology yields no clear prediction for the initial magnetic field strength, efficient dynamo action may compensate for initially weak seed fields via rapid amplification. In particular, the small-scale…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-12 M. A. Latif , D. R. G. Schleicher , W. Schmidt , J. Niemeyer

The turbulent magnetic diffusivity tensor is determined in the presence of rotation or shear. The question is addressed whether dynamo action from the shear-current effect can explain large-scale magnetic field generation found in…

Astrophysics · Physics 2010-11-05 A. Brandenburg , K. -H. Rädler , M. Rheinhardt , P. J. Käpylä

We study the impact of rotation on the hydrodynamic evolution of convective vortices during stellar collapse. Using linear hydrodynamics equations, we study the evolution of the vortices from their initial radii in convective shells down to…

Solar and Stellar Astrophysics · Physics 2021-03-17 E. Abdikamalov , T. Foglizzo , O. Mukazhanov

In this study we discuss two key issues related to a small-scale dynamo instability at low magnetic Prandtl numbers and large magnetic Reynolds numbers, namely: (i) the scaling for the growth rate of small-scale dynamo instability in the…

Solar and Stellar Astrophysics · Physics 2015-06-03 N. Kleeorin , I. Rogachevskii

We study a harmonically-confined Bose-Einstein condensate under rotation. Vortex lattice configurations are investigated through a variational approach. Vortices with more than a unit of angular momentum are not stable. We explicitly show…

Condensed Matter · Physics 2009-11-07 V. Subrahmanyam

We investigate the effect of inertial particles dispersed in a circular patch of finite radius on the stability of a two-dimensional Rankine vortex in semi-dilute dusty flows. Unlike the particle-free case where no unstable modes exist, we…

Fluid Dynamics · Physics 2022-10-05 Shuai Shuai , Darish Jeswin Dhas , Anubhab Roy , M. Houssem Kasbaoui

The role of shear in alleviating catastrophic quenching by shedding small-scale magnetic helicity through fluxes along contours of constant shear is discussed. The level of quenching of the dynamo effect depends on the quenched value of the…

Astrophysics · Physics 2008-08-08 Axel Brandenburg

We investigate the influence of dust particle size evolution on non-ideal magnetohydrodynamic effects during the collapsing phase of star-forming cores, taking both the turbulence intensity in the collapsing cloud core and the fragmentation…

Astrophysics of Galaxies · Physics 2023-05-03 Yoshihiro Kawasaki , Masahiro N. Machida

The evolution of the magnetic field from the large-scale dynamo is considered a central feature of the accretion disk around a black hole. The resulting low-frequency oscillations introduced from the growth and decay of the field strength,…

High Energy Astrophysical Phenomena · Physics 2018-07-11 J. Drew Hogg , Christopher Reynolds

Using direct simulations of hydromagnetic turbulence driven by random polarized waves it is shown that dynamo action is possible over a wide range of magnetic Prandtl numbers from 10^-3 to 1. Triply periodic boundary conditions are being…

Astrophysics · Physics 2010-01-15 Axel Brandenburg

The transport of angular momentum in the outward direction is the fundamental requirement for accretion to proceed in an accretion disc. This objective can be achieved if the accretion flow is turbulent. Instabilities are one of the sources…

Astrophysics of Galaxies · Physics 2014-11-21 Mradul Sharma