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The Global Magnetorotational Instability (MRI) is investigated for a configuration in which the rotation frequency changes only in a narrow transition region. If the vertical wavelength of the unstable mode is of the same order or smaller…

Instrumentation and Methods for Astrophysics · Physics 2011-02-11 J. Pino , S. M. Mahajan

We present two-dimensional particle-in-cell (PIC) simulations of the fully kinetic collisionless magnetorotational instability (MRI) in weakly magnetized (high $\beta$) pair plasma. The central result of this numerical analysis is the…

High Energy Astrophysical Phenomena · Physics 2018-06-27 Giannandrea Inchingolo , Thomas Grismayer , Nuno F. Loureiro , Ricardo A. Fonseca , Luis O. Silva

The magneto-rotational instability (MRI) is considered to be a promising mechanism to amplify the magnetic field in fast rotating protoneutron stars. In contrast to accretion disks, radial buoyancy driven by entropy and lepton fraction…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Jerome Guilet , Ewald Mueller

We examine whether the magnetorotational instability (MRI) can serve as a mechanism of angular momentum transport in circumplanetary disks. For the MRI to operate the ionization degree must be sufficiently high and the magnetic pressure…

Earth and Planetary Astrophysics · Physics 2015-06-18 Yuri I. Fujii , Satoshi Okuzumi , Takayuki Tanigawa , Shu-ichiro Inutsuka

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

Previous studies of the nonlinear regime of the magnetorotational instability in one particular type of shearing box model -- unstratified with no net magnetic flux -- find that without explicit dissipation (viscosity and resistivity) the…

High Energy Astrophysical Phenomena · Physics 2016-01-27 Ji-Ming Shi , James M. Stone , Chelsea X. Huang

The magnetorotational instability (MRI) is a fundamental process of accretion disk physics, but its saturation mechanism remains poorly understood despite considerable theoretical and computational effort. We present a multiple scales…

High Energy Astrophysical Phenomena · Physics 2017-05-24 S. E. Clark , Jeffrey S. Oishi

The magneto-rotational instability is presently the most promising source of turbulent transport in accretion disks. However, some important issues still need to be addressed to quantify the role of MRI in disks; in particular no systematic…

Astrophysics · Physics 2009-06-23 G. Lesur , P-Y. Longaretti

The nonaxisymmetric azimuthal magnetorotational instability is studied for hydromagnetic Taylor-Couette flows between cylinders of finite electrical conductivity. We find that the magnetic Prandtl number Pm determines whether perfectly…

Fluid Dynamics · Physics 2018-10-10 Günther Rüdiger , Manfred Schultz , Frank Stefani , Rainer Hollerbach

The magnetorotational instability (MRI) has been suggested to have an important role on the dynamics of accretion disks. We investigate MRI as an alternative way for guiding the plasma from the disk to the funnel flow at the…

High Energy Astrophysical Phenomena · Physics 2012-10-08 S. Dogan , E. R. Pekunlu

Magnetic fields are critical at many scales to galactic dynamics and structure, including multiphase pressure balance, dust processing, and star formation. Dynamo action determines their dynamical structure and strength. Simulations of…

Astrophysics of Galaxies · Physics 2026-02-17 Frederick A. Gent , Mordecai-Mark Mac Low , Maarit J. Korpi-Lagg , Touko Puro , Matthias Reinhardt

Magnetorotational instability (MRI) in a convectively-stable layer around the neutrinosphere is simulated by a three-dimensional model of supernova core. To resolve MRI-unstable modes, a thin layer approximation considering only the radial…

High Energy Astrophysical Phenomena · Physics 2015-06-23 Youhei Masada , Tomoya Takiwaki , Kei Kotake

We study the saturation near threshold of the axisymmetric magnetorotational instability (MRI) of a viscous, resistive, incompressible fluid in a thin-gap Taylor-Couette configuration. A vertical magnetic field, Keplerian shear and no-slip,…

Astrophysics · Physics 2009-11-13 O. M. Umurhan , O. Regev , K. Menou

While the saturated magnetic energy is independent of viscosity in dynamo experiments, it remains viscosity-dependent in state-of-the-art 3D direct numerical simulations (DNS). Extrapolating such viscous scaling-laws to realistic parameter…

Fluid Dynamics · Physics 2017-12-20 Kannabiran Seshasayanan , Basile Gallet , Alexandros Alexakis

We report an extensive numerical study of the small-scale turbulent dynamo at large magnetic Prandtl numbers Pm. A Pm scan is given for the model case of low-Reynolds-number turbulence. We concentrate on three topics: magnetic-energy…

Astrophysics · Physics 2008-11-26 A. A. Schekochihin , S. C. Cowley , S. F. Taylor , J. L. Maron , J. C. McWilliams

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 magnetorotational instability (MRI) occurs when a weak magnetic field destabilises a rotating, electrically conducting fluid with inwardly increasing angular velocity. The MRI is essential to astrophysical disk theory where the shear is…

Magnetorotational instability (MRI) is one of the fundamental processes in astrophysics, driving angular momentum transport and mass accretion in a wide variety of cosmic objects. Despite much theoretical/numerical and experimental efforts…

Fluid Dynamics · Physics 2017-11-28 G. Mamatsashvili , F. Stefani , A. Guseva , M. Avila

We investigate the linear growth and vertical structure of the magnetorotational instability (MRI) in weakly ionised, stratified accretion discs. The magnetic field is initially vertical and dust grains are assumed to have settled towards…

Astrophysics · Physics 2009-11-10 Raquel Salmeron , Mark Wardle

In this paper, we investigate numerically the flow of an electrically conducting fluid in a cylindrical Taylor-Couette flow when an axial magnetic field is applied. To minimize Ekman recirculation due to vertical no-slip boundaries, two…

Fluid Dynamics · Physics 2015-06-03 Christophe Gissinger , Jeremy Goodman , Hantao Ji