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Related papers: Parametric instability of the helical dynamo

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Turbulence is typically not in equilibrium, i.e. mean quantities such as the mean energy and helicity are typically time-dependent. The effect of non-stationarity on the turbulent hydromagnetic dynamo process is studied here with the use of…

Fluid Dynamics · Physics 2023-08-10 Krzysztof A. Mizerski , Nobumitsu Yokoi , Axel Brandenburg

Numerical simulations of the magnetorotational instability (MRI) with zero initial net flux in a non-stratified isothermal cubic domain are used to demonstrate the importance of magnetic boundary conditions.In fully periodic systems the…

High Energy Astrophysical Phenomena · Physics 2011-07-08 Petri J. Käpylä , Maarit J. Korpi

The possibility that the magnetic shear-flow instability (MRI, Balbus-Hawley instability) might give rise to turbulence in a cylindric Couette flow is investigated through numerical simulations. The study is linear and the fluid flow is…

Astrophysics · Physics 2009-11-06 G. Rüdiger , Y. Zhang

We introduce a new measure for the stability of structures, such as the cross-section of the deck of a suspension bridge, subject to a 2D fluid force, such as the lift exerted by a laminar wind. We consider a wide class of possible flows,…

Analysis of PDEs · Mathematics 2024-04-09 Edoardo Bocchi , Filippo Gazzola

We review the results obtained by three successful fluid dynamo experiments and discuss what has been learnt from them about the effect of turbulence on the dynamo threshold and saturation. We then discuss several questions that are still…

Fluid Dynamics · Physics 2009-11-13 F. Petrelis , N. Mordant , S. Fauve

In this paper, we use the well-known background method to obtain a rigorous lower bound on the volume flow rate through a helical pipe driven by a pressure differential in the limit of large Reynolds number. As a consequence, we also obtain…

Fluid Dynamics · Physics 2020-10-28 Anuj Kumar

The flow of viscoelastic fluids in channels and pipes remain poorly understood, particularly at low Reynolds numbers. Here, we investigate the flow of polymeric solutions in straight channels using pressure measurements and particle…

Fluid Dynamics · Physics 2019-11-13 Boyang Qin , Paul F. Salipante , Steven D. Hudson , Paulo E. Arratia

The VKS experiment has evidenced dynamo action in a highly turbulent liquid sodium von K\'arm\'an flow [R. Monchaux et al., Phys. Rev. Lett. {\bf 98}, 044502 (2007)]. However, the existence and the onset of a dynamo happen to depend on the…

Fluid Dynamics · Physics 2011-06-10 A. Pinter , B. Dubrulle , F. Daviaud , J. Leorat

Dynamical tunnelling between symmetry-related stable modes is studied in the periodically driven pendulum. We present strong evidence that the tunnelling process is governed by nonlinear resonances that manifest within the regular…

Quantum Physics · Physics 2007-05-23 Amaury Mouchet , Christopher Eltschka , Peter Schlagheck

We carry out a linear stability analysis of a magnetized relativistic rotating cylindrical jet flow using the approximation of zero thermal pressure. We identify several modes of instability in the jet: Kelvin-Helmholtz, current driven and…

High Energy Astrophysical Phenomena · Physics 2019-03-13 Gianluigi Bodo , George Mamatsashvili , Paola Rossi , Andrea Mignone

Here we build some effective boundary conditions to be used in numerical calculations in order to avoid the thin meshing usually required in problems involving Hartmann layers near a locally plane wall. Wall model are provided for both…

Fluid Dynamics · Physics 2020-06-15 Alban Pothérat , Joël Sommeria , René Moreau

This paper concerns the structural stability of smooth cylindrical symmetric transonic flows in a concentric cylinder under helically symmetric perturbation of suitable boundary conditions. The deformation-curl decomposition developed by…

Analysis of PDEs · Mathematics 2024-03-20 Yi Ke , Shangkun Weng

This manuscript has been accepted for publication in Physical Review Fluids, see https://journals.aps.org/prfluids/accepted/53075Se8O0b1b109b1cc0061b280aaa122f0f92dc. The stability of a pulsatile quasi-two-dimensional duct flow was…

Fluid Dynamics · Physics 2021-05-12 Christopher J. Camobreco , Alban Pothérat , Gregory J. Sheard

The aim of this Letter is to characterize the flow regimes of suspensions of finite-size rigid particles in a viscous fluid at finite inertia. We explore the system behavior as function of the particle volume fraction and the Reynolds…

Fluid Dynamics · Physics 2015-06-18 Iman Lashgari , Francesco Picano , Wim-Paul Breugem , Luca Brandt

The flow of frictionless granular particles is studied with stress-controlled discrete element modeling simulations for systems varying in size from 300 to 100,000 particles. The volume fraction and shear stress ratio $\mu$ are relatively…

Soft Condensed Matter · Physics 2022-01-12 A. P. Santos , Ishan Srivastava , Leonardo E. Silbert , Jeremy B. Lechman , Gary S. Grest

Fluctuation dynamos provide a robust mechanism for amplifying weak seed magnetic fields in turbulent astrophysical plasmas. However, their behaviour in the highly compressible regimes characteristic of the interstellar medium remains…

Astrophysics of Galaxies · Physics 2026-02-18 Ameya Uday Nagdeo , Sharanya Sur , Bhargav Vaidya

A modelling methodology to reproduce the experimental measurements of a turbulent flow under the presence of symmetry is presented. The flow is a three-dimensional wake generated by an axisymmetric body. We show that the dynamics of the…

Fluid Dynamics · Physics 2023-07-19 G. Rigas , A. S. Morgans , R. D. Brackston , J. F. Morrison

Interactions between fluids and elastic solids are ubiquitous in application ranging from aeronautical and civil engineering to physiological flows. Here we study the pulsatile flow through a two-dimensional Starling resistor as a simple…

Fluid Dynamics · Physics 2021-01-15 Duo Xu , Matthias Heil , Thomas Seeböck , Marc Avila

The Tayler instability of an azimuthal magnetic field with one or two ``rings'' along the radius is studied for an axially unbounded Taylor-Couette flow. The rotation law of the conducting fluid is a quasi-Keplerian one. Without rotation…

Solar and Stellar Astrophysics · Physics 2025-03-18 Günther Rüdiger , Manfred Schultz

The flow of an electrically conducting fluid driven by a traveling magnetic field imposed at the endcaps of a cylindrical annulus is numerically studied. At sufficiently large magnetic Reynolds number, the system undergoes a transition from…

Fluid Dynamics · Physics 2018-06-27 Sandeep R. Kanuganti , Stephan Fauve , Christophe Gissinger