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Related papers: Nonhelical turbulent dynamos: shocks and shear

200 papers

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…

Fluid Dynamics · Physics 2022-11-23 Ming Yan , Michael A. Calkins

This work presents numerical results on the transport of heat and chemical species by shear-induced turbulence in strongly stratified but thermally diffusive environments. The shear instabilities driven in this regime are sometimes called…

Solar and Stellar Astrophysics · Physics 2016-04-20 Pascale Garaud , Logithan Kulenthirarajah

We present numerical simulations of laminar and turbulent channel flow of an elastoviscoplastic fluid. The non-Newtonian flow is simulated by solving the full incompressible Navier-Stokes equations coupled with the evolution equation for…

Fluid Dynamics · Physics 2018-07-17 Marco Edoardo Rosti , Daulet Izbassarov , Outi Tammisola , Sarah Hormozi , Luca Brandt

Magnetic dynamo action caused by the magnetorotational instability is studied in the shearing-box approximation with no imposed net magnetic flux. Consistent with recent studies, the dynamo action is found to be sensitive to the aspect…

Solar and Stellar Astrophysics · Physics 2017-04-28 Justin Walker , Stanislav Boldyrev

We investigate three-dimensional turbulence in a stably stratified fluid driven by a vertically sheared Kolmogorov flow using direct numerical simulations of the Boussinesq equations. As stratification increases, mean profiles evolve toward…

Fluid Dynamics · Physics 2025-12-16 Alessandro Sozza , Andrea Maffioli

This paper presents a new theory of turbulent mixing in stirred reactors. The degree of homogeneity of a mixed fluid may be characterized by the Kolmogorov micro-scale. The smaller its value, the better homogeneity. The micro-scale scales…

Fluid Dynamics · Physics 2016-04-26 Helmut Z. Baumert , Bernhard Wessling

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…

Fluid Dynamics · Physics 2009-11-13 P. D. Mininni , A. Alexakis , A. Pouquet

We report a series of numerical simulations showing that the critical magnetic Reynolds number Rm_c for the nonhelical small-scale dynamo depends on the Reynolds number Re. Namely, the dynamo is shut down if the magnetic Prandtl number…

Astrophysics · Physics 2009-11-16 A. A. Schekochihin , S. C. Cowley , J. L. Maron , J. C. McWilliams

The self-excitation of magnetic field by a spiral Couette flow between two coaxial cylinders is considered. We solve numerically the fully nonlinear, three-dimensional MHD equations for magnetic Prandtl numbers Pm (ratio of kinematic…

Astrophysics · Physics 2009-11-06 Wolfgang Dobler , Anvar Shukurov , Axel Brandenburg

The onset of shear flow turbulence is characterized by turbulent patches bounded by regions of laminar flow. At low Reynolds numbers localized turbulence relaminarises, raising the question of whether it is transient in nature or it becomes…

Fluid Dynamics · Physics 2014-03-31 M. Avila , A. P. Willis , B. Hof

Magnetic fields, compressibility and turbulence are important factors in many terrestrial and astrophysical processes. While energy dynamics, i.e. how energy is transferred within and between kinetic and magnetic reservoirs, has been…

Plasma Physics · Physics 2017-10-04 Philipp Grete , Brian W. O'Shea , Kris Beckwith , Wolfram Schmidt , Andrew Christlieb

Turbulent drag reduction through streamwise travelling waves of spanwise wall oscillation is investigated over a wide range of Reynolds numbers. Here, in Part 1, wall-resolved large-eddy simulations in a channel flow are conducted to…

We investigate numerically the self-sustained dynamo action in a spinning sphere whose sense of rotation reverses periodically. This system serves as a simple model of a dynamo in small bodies powered by frequent collisions. It is found…

Geophysics · Physics 2015-06-18 Xing Wei , Rainer Arlt , Andreas Tilgner

Active turbulence is a paradigmatic and fascinating example of self-organized motion at large scales occurring in active matter. We employ massive hydrodynamic simulations of suspensions of resolved model microswimmers to tackle the…

Soft Condensed Matter · Physics 2025-03-18 Antonio Gascó , Ignacio Pagonabarraga , Andrea Scagliarini

The nonlinear mean-field dynamo due to a shear-current effect in a nonhelical homogeneous turbulence with a mean velocity shear is discussed. The transport of magnetic helicity as a dynamical nonlinearity is taken into account. The…

Astrophysics · Physics 2009-11-11 I. Rogachevskii , N. Kleeorin , E. Liverts

The progress in our understanding of several aspects of turbulent Rayleigh-Benard convection is reviewed. The focus is on the question of how the Nusselt number and the Reynolds number depend on the Rayleigh number Ra and the Prandtl number…

Fluid Dynamics · Physics 2015-05-13 Guenter Ahlers , Siegfried Grossmann , Detlef Lohse

The emergence of large-scale spatial modulations of turbulent channel flow, as the Reynolds number is decreased, is addressed numerically using the framework of linear stability analysis. Such modulations are known as the precursors of…

We study the dynamo threshold of a helical flow made of a mean (stationary) plus a fluctuating part. Two flow geometries are studied, either (i) solid body or (ii) smooth. Two well-known resonant dynamo conditions, elaborated for stationary…

Fluid Dynamics · Physics 2009-11-13 Marine Peyrot , Franck Plunian , Christiane Normand

The shear-current effect in a nonrotating homogeneous turbulent convection with a large-scale constant shear is studied. The large-scale velocity shear causes anisotropy of turbulent convection, which produces the mean electromotive force…

Astrophysics · Physics 2008-11-26 I. Rogachevskii , N. Kleeorin

Dynamics of flexible non-Brownian fibers in shear flow at low-Reynolds-number are analyzed numerically for a wide range of the ratios A of the fiber bending force to the viscous drag force. Initially, the fibers are aligned with the flow,…

Soft Condensed Matter · Physics 2015-10-28 Agnieszka M. Slowicka , Eligiusz Wajnryb , Maria L. Ekiel-Jezewska