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We construct self-similar inflow-outflow solutions for a hot viscous-resistive accretion flow with large scale magnetic fields that have odd symmetry with respect to the equatorial plane in $B_\theta$, and even symmetry in $B_r$ and…

High Energy Astrophysical Phenomena · Physics 2016-03-30 Maryam Samadi , Shahram Abbassi

This paper explores the effects of large-scale magnetic fields in hot accretion flows for asymmetric configurations with respect to the equatorial plane. The solutions that we have found show that the large-scale asymmetric magnetic field…

High Energy Astrophysical Phenomena · Physics 2017-07-26 Maryam Samadi , Shahram Abbassi , Richard Lovelace

The small-scale kinematic dynamo in a two-dimensional chaotic flow is studied. The analytic approach is developed in framework of the Kraichnan-Kazantsev model. It is shown that the growth of magnetic field $\bm{B}$ fluctuations stops at…

Chaotic Dynamics · Physics 2016-03-30 Igor Kolokolov

In this paper we investigate the dynamics of magnetic helicity in magnetohydrodynamic (MHD) turbulent flows focusing at scales larger than the forcing scale. Our results show a nonlocal inverse cascade of magnetic helicity, which occurs…

Fluid Dynamics · Physics 2017-05-23 Moritz Linkmann , Vassilios Dallas

The Magneto-hydrodynamic (MHD) equations in the presence of a guiding magnetic field are investigated by means of direct numerical simulations. The basis of the investigation consists of 9 runs forced at the small scales. The results…

Fluid Dynamics · Physics 2015-05-30 Alexandros Alexakis

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

It is shown, that the saturated $\alpha$-effect taken from the nonlinear dynamo equations for the thin disk can still produce exponentially growing magnetic field in the case, when this field does not feed back on the $\alpha$. For negative…

Fluid Dynamics · Physics 2015-05-18 M. Reshetnyak

We consider the stability of a configuration consisting of a vertical magnetic field in a planar flow on elliptical streamlines in ideal hydromagnetics. In the absence of a magnetic field the elliptical flow is universally unstable (the…

Astrophysics · Physics 2009-11-10 Norman R. Lebovitz , Ellen G. Zweibel

We demonstrate here that ultrathin ferromagnetic Pt/Co/Pt films with perpendicular magnetic anisotropy exhibit a sizeable Dzyaloshinskii-Moriya interaction (DMI) effect. Such a DMI effect modifies the domain-wall (DW) energy density and…

Materials Science · Physics 2017-04-25 Soong-Geun Je , Duck-Ho Kim , Sang-Cheol Yoo , Byoung-Chul Min , Kyung-Jin Lee , Sug-Bong Choe

In the present paper, we study a new type of large-scale instability, which arises in obliquely rotating electroconductive fluids with a small-scale external force of zero helicity. This force excites small-scale velocity oscillations with…

Plasma Physics · Physics 2017-11-27 M. I. Kopp , A. V. Tur , V. V. Yanovsky

I consider the problem of weakly nonlinear stability of three-dimensional parity-invariant magnetohydrodynamic systems to perturbations, involving large scales. I assume that the MHD state, the stability of which I investigate, does not…

Chaotic Dynamics · Physics 2007-05-23 V. Zheligovsky

An axisymmetric magnetic field is applied to a spherical, turbulent flow of liquid sodium. An induced magnetic dipole moment is measured which cannot be generated by the interaction of the axisymmetric mean flow with the applied field,…

Plasma Physics · Physics 2007-05-23 E. J. Spence , M. D. Nornberg , C. M. Jacobson , R. D. Kendrick , C. B. Forest

The effect of magnetic field on the nonlinear growth rate of Rayleigh-Taylor instability induced two fluid interfacial structures has been investigated. The magnetic field is assumed to be parallel to the plane of the two fluid interface…

Plasma Physics · Physics 2015-05-27 M. R. Gupta , Labakanta Mandal , Sourav Roy , Manoranjan Khan

A numerical model of isotropic homogeneous turbulence with helical forcing is investigated. The resulting flow, which is essentially the prototype of the alpha^2 dynamo of mean-field dynamo theory, produces strong dynamo action with an…

Astrophysics · Physics 2010-04-06 Axel Brandenburg

We introduce a stochastic model for a passive magnetic field in a three dimensional thin domain. The velocity field, white in time and modelling phenomenologically a turbulent fluid, acts on the magnetic field as a transport-stretching…

Probability · Mathematics 2024-02-06 Federico Butori , Franco Flandoli , Eliseo Luongo

An effect of sheared large-scale motions on a mean electromotive force in a nonrotating turbulent flow of a conducting fluid is studied. It is demonstrated that in a homogeneous divergence-free turbulent flow the alpha-effect does not…

Astrophysics · Physics 2009-11-07 I. Rogachevskii , N. Kleeorin

Using numerical simulations at moderate magnetic Reynolds numbers up to 220 it is shown that in the kinematic regime, isotropic helical turbulence leads to an alpha effect and a turbulent diffusivity whose values are independent of the…

Astrophysics · Physics 2008-03-10 Sharanya Sur , Axel Brandenburg , Kandaswamy Subramanian

The evolution of large-scale magnetic fields in disk galaxies is investigated numerically. The gasdynamical simulations in a disk perturbed by spiral or bar potential are incorporated into the kinematic calculations of induction equations…

Astrophysics · Physics 2007-05-23 K. Otmianowska-Mazur , M. Chiba

We propose a phenomenological theory of strong incompressible magnetohydrodynamic turbulence in the presence of a strong large-scale external magnetic field. We argue that in the inertial range of scales, magnetic-field and velocity-field…

Astrophysics · Physics 2007-05-23 Stanislav Boldyrev

A weak fluctuating magnetic field embedded into a turbulent conducting medium grows exponentially while its characteristic scale decays. In the ISM and protogalactic plasmas, the magnetic Pr is very large, so a broad spectrum of growing…

Astrophysics · Physics 2008-11-26 Alexander Schekochihin , Steven Cowley , Jason Maron , Leonid Malyshkin
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