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Related papers: Magnetic instability in a sheared azimuthal flow

200 papers

The magnetorotational instability (MRI) may dominate outward transport of angular momentum in accretion disks, allowing material to fall onto the central object. Previous work has established that the MRI can drive a mean-field dynamo,…

Solar and Stellar Astrophysics · Physics 2015-05-27 Jeffrey S. Oishi , Mordecai-Mark Mac Low

If a magnetic field normal to the surface of a magnetic fluid is increased beyond a critical value a spontaneous deformation of the surface arises (normal field instability). The instability is subcritical and leads to peaks of a…

patt-sol · Physics 2016-09-08 Thomas Mahr , Ingo Rehberg

The amplification of astrophysical magnetic fields takes place via dynamo instability in turbulent environments. The presence of vorticity is crucial for the dynamo to happen. However, the role of vorticity is not yet fully understood. This…

Astrophysics of Galaxies · Physics 2024-12-11 Albert Elias-López , Fabio del Sordo , Daniele Viganò

The stability of large-scale magnetic fields in rotating stars is explored, using 3D numerical hydrodynamics to follow the evolution of an initial poloidal field. It is found that the field is subject to an instability, located initially on…

Astrophysics · Physics 2009-11-13 J. Braithwaite

Motivated by the significant interaction of convection, rotation and magnetic field in many astrophysical objects, we investigate the interplay between large-scale flows driven by rotating convection and an imposed magnetic field. We…

Solar and Stellar Astrophysics · Physics 2016-11-23 Laura K. Currie

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

We study the dynamo instability for a Kazantsev-Kraichnan flow with three velocity components that depends only on two-dimensions u = (u(x, y, t), v(x, y, t), w(x, y, t)) often referred to as 2.5 dimensional (2.5D) flow. Within the…

Fluid Dynamics · Physics 2016-11-03 K. Seshasayanan , A. Alexakis

We establish a variational framework for nonlinear instabilities in a setting of the ideal magnetohydrodynamic (MHD) equations. We apply a variational method to various kind of smooth steady states which are shown to be nonlinearly unstable…

Analysis of PDEs · Mathematics 2007-05-23 Hyung Ju Hwang

We study the stability of two-fluid flow through a plane channel at Reynolds numbers of a hundred to a thousand in the linear and nonlinear regimes. The two fluids have the same density but different viscosities. The fluids, when miscible,…

Fluid Dynamics · Physics 2021-01-27 Kirti Chandra Sahu , Rama Govindarajan

We consider the linear stability to three-dimensional perturbations of two-dimensional nonlinear magnetohydrodynamic basic states obtained from a specified forcing function in the presence of an imposed initially uniform magnetic field of…

Fluid Dynamics · Physics 2009-06-17 D. W. Hughes , M. R. E. Proctor

This research is focused on linear analysis of a plane-parallel flow stability in a transverse magnetic field (Hartmann flow) within a convective approximation. We derive and solve equations describing the perturbation growth. Perturbation…

Fluid Dynamics · Physics 2015-02-27 I. Yu. Kalashnikov

It is known that in a hydrodynamic Taylor-Couette system uniform rotation or a rotation law with positive shear ('super-rotation') are linearly stable. It is also known that a conducting fluid under the presence of a sufficiently strong…

Solar and Stellar Astrophysics · Physics 2016-02-17 G. Rüdiger , M. Schultz , M. Gellert , F. Stefani

The non-linear Hall term present in the induction equation in the electron-magneto-hydrodynamics limit is responsible for the Hall drift of the magnetic field and, in some cases, for the so-called Hall instability. We investigate whether or…

Solar and Stellar Astrophysics · Physics 2012-03-28 Jose A. Pons , Ulrich Geppert

A modal stability analysis shows that pressure-driven pipe flow of an Oldroyd-B fluid is linearly unstable to axisymmetric perturbations, in stark contrast to its Newtonian counterpart which is linearly stable at all Reynolds numbers. The…

Fluid Dynamics · Physics 2020-12-09 Indresh Chaudhary , Piyush Garg , Ganesh Subramanian , Viswanathan Shankar

The linear theory for rotating compressible convection in a plane layer geometry is presented for the astrophysically-relevant case of low Prandtl number gases. When the rotation rate of the system is large, the flow remains geostrophically…

Geophysics · Physics 2015-03-02 Michael A. Calkins , Keith Julien , Philippe Marti

A concise review is given of astrophysically motivated experimental and theoretical research on Taylor-Couette flow. The flows of interest rotate differentially with inner cylinder faster than outer one but are linearly stable against…

Fluid Dynamics · Physics 2022-12-20 H. Ji , J. Goodman

We study the energy stability of pressure-driven laminar magnetohydrodynamic flow in a rectangular duct with transverse homogeneous magnetic field and electrically insulating walls. For sufficiently strong fields, the laminar velocity…

Fluid Dynamics · Physics 2024-05-29 Thomas Boeck , Mattias Brynjell-Rahkola , Yohann Duguet

We investigate the stability of katabatic slope flows over an infinitely wide and uniformly cooled planar surface subject to an additional forcing due to a uniform downslope wind field aloft. We adopt an extension of Prandtl's original…

Fluid Dynamics · Physics 2020-02-19 Cheng-Nian Xiao , Inanc Senocak

Inspired by the experiment from Moresco \& Alboussi\`ere (2004, J. Fluid Mech.), we study the stability of a liquid metal flow in a rectangular, electrically insulating duct with a steady homogeneous transverse magnetic field. The Lorentz…

Fluid Dynamics · Physics 2020-06-09 Alban Pothérat

Differential rotation occurs in conducting flows in accretion disks and planetary cores. In such systems, the magnetorotational instability can arise from coupling Lorentz and centrifugal forces to cause large radial angular momentum…