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Related papers: Shear dynamo problem: Quasilinear kinematic theory

200 papers

We re-examine the nature of the turbulent magnetic diffusivity tensor of mean field electrodynamics and show that an inconsistency arises if it is calculated via consideration of time-independent magnetic fields. Specifically, the predicted…

Solar and Stellar Astrophysics · Physics 2010-01-14 David W. Hughes , Michael R. E. Proctor

We investigate the growth and structure of magnetic fields amplified by kinematic dynamo action in turbulence with non-zero kinetic helicity. We assume a simple Gaussian velocity correlation tensor, which allows us to consider very large…

Astrophysics · Physics 2009-11-13 Leonid Malyshkin , Stanislav Boldyrev

Using a dynamical density functional theory we analyze the density profile of a colloidal liquid near a wall under shear flow. Due to the symmetries of the system considered, the naive application of dynamical density functional theory does…

Soft Condensed Matter · Physics 2015-05-20 J. M. Brader , M. Krüger

The motion of a deformable active particle in linear shear flow is explored theoretically. Based on symmetry considerations, in two spatial dimensions, we propose coupled nonlinear dynamical equations for the particle position, velocity,…

Soft Condensed Matter · Physics 2014-01-28 Mitsusuke Tarama , Andreas M. Menzel , Borge ten Hagen , Raphael Wittkowski , Takao Ohta , Hartmut Löwen

Small scale turbulent dynamo action in compressible transonic turbulence is discussed. It is shown that the critical value of the magnetic Reynolds number displays a bimodal behavior and changes from a typical value of 35 for small Mach…

Astrophysics · Physics 2007-05-23 A. Brandenburg , N. E. L. Haugen , A. J. Mee

The transition to intermittent mean--field dynamos is studied using numerical simulations of isotropic magnetohydrodynamic turbulence driven by a helical flow. The low-Prandtl number regime is investigated by keeping the kinematic viscosity…

Solar and Stellar Astrophysics · Physics 2015-05-13 Erico L. Rempel , Michael R. E. Proctor , Abraham C. -L. Chian

Using a rotating flat layer heated from below as an example, we consider effects which lead to stabilizing an exponentially growing magnetic field in magnetostrophic convection in transition from the kinematic dynamo to the full non-linear…

Fluid Dynamics · Physics 2015-05-18 P. Hejda , M. Reshetnyak

Buneman instability is often driven in magnetic reconnection. Understanding how velocity shear in the beams driving the Buneman instability affects the growth and saturation of waves is relevant to turbulence, heating, and diffusion in…

Plasma Physics · Physics 2015-05-28 H. Che , M. V. Goldman , D. L. Newman

Solar, stellar and galactic large-scale magnetic fields are originated due to a combined action of non-uniform (differential) rotation and helical motions of plasma via mean-field dynamos. Usually, nonlinear mean-field dynamo theories take…

Solar and Stellar Astrophysics · Physics 2024-04-19 I. Rogachevskii , N. Kleeorin

The competition between the drive and stabilization of plasma microinstabilities by sheared flow is investigated, focusing on the ion temperature gradient mode. Using a twisting mode representation in sheared slab geometry, the…

Plasma Physics · Physics 2015-05-19 Sarah L. Newton , Steve C. Cowley , Nuno F. Loureiro

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

The transport of slightly deformable chiral objects in a uniform shear flow is investigated. Depending on the equilibrium configuration one finds up to four different asymptotic states that can be distinguished by a lateral drift velocity…

Soft Condensed Matter · Physics 2012-07-06 Peter Talkner , Gert-Ludwig Ingold , Peter Hanggi

In Keplerian accretion disks, turbulence and magnetic fields may be jointly excited through a subcritical dynamo process involving the magnetorotational instability (MRI). High-resolution simulations exhibit a tendency towards statistical…

High Energy Astrophysical Phenomena · Physics 2017-02-08 A. Riols , F. Rincon , C. Cossu , G. Lesur , G. I. Ogilvie , P-Y. Longaretti

We consider the effect of vertical outflows on the mean-field dynamo in a thin disk. These outflows could be due to winds or magnetic buoyancy. We analyse both two-dimensional finite-difference numerical solutions of the axisymmetric dynamo…

Astrophysics · Physics 2009-10-31 A. Bardou , B. v. Rekowski , W. Dobler , A. Brandenburg , A. Shukurov

The linear non-modal kinetic theory of the kinetic drift-Alfven instability of plasma shear flows reveals the temporal non-modal growth with growing with time growth rate. The turbulent scattering of the sheared modes on ions accelerates…

Plasma Physics · Physics 2015-06-15 V. V. Mikhailenko , V. S. Mikhailenko , Hae June Lee , M. E. Koepke

The kinematic dynamo problem is investigated for the flow of a conducting fluid in a cylindrical, periodic tube with conducting walls. The methods used are an eigenvalue analysis of the steady regime, and the three-dimensional solution of…

Astrophysics · Physics 2009-11-07 Wolfgang Dobler , Peter Frick , Rodion Stepanov

The consequences of the shear-induced alpha effect to the long-term modulation of magnetic activity are examined with the help of the axisymmetric numerical dynamo model that includes the self-consistent description of the angular momentum…

Astrophysics · Physics 2007-12-18 V. V. Pipin

The problem of three-dimensional combined magnetic and velocity shear driven instabilities of a compressible magnetized jet modeled with a plane neutral/current double vortex sheet in the framework of the resistive magnetohydrodynamics is…

Plasma Physics · Physics 2015-05-13 Lapo Bettarini , Simone Landi , Marco Velli , Pasquale Londrillo

In many plasma systems, introducing a small background shear flow is enough to stabilize the system linearly. The nonlinear dynamics are much less sensitive to sheared flows than the average linear growthrates, and very small amplitude…

Plasma Physics · Physics 2018-01-17 Chris C. T. Pringle , Ben F. McMillan , Bogdan Teaca

Observations of protostellar disks indicate the presence of the magnetic field of thermal (or superthermal) strength. In such a strong magnetic field, many MHD instabilities responsible for turbulent transport of the angular momentum are…

Astrophysics · Physics 2009-11-13 Alfio Bonanno , Vadim Urpin