Saturation of the magnetorotational instability
نویسندگان
چکیده
An analytical theory is developed that describes asymptotically exactly the process of nonlinear saturation of the magnetorotational instability in a model problem employing a linear shear flow in a uniformly rotating channel. The theory shows that the instability saturates by modifying the shear responsible for it. The saturation process requires both viscous and Ohmic dissipation. The theory also describes the approach from small-amplitude perturbations to the final strongly nonlinear saturated state. © 2005 American Institute of Physics. DOI: 10.1063/1.2047592
منابع مشابه
Magnetorotational instability: recent developments.
The magnetorotational instability is believed to play an important role in accretion disc physics in extracting angular momentum from the disc and allowing accretion to take place. For this reason the instability has been the subject of numerous numerical simulations and, increasingly, laboratory experiments. In this review, recent developments in both areas are surveyed, and a new theoretical ...
متن کاملAn asymptotically exact reduced PDE model for the magnetorotational instability: derivation and numerical simulations
Taking advantage of disparate spatio-temporal scales relevant to astrophysics and laboratory experiments, we derive asymptotically exact reduced partial differential equation models for the magnetorotational instability. These models extend recent single-mode formulations leading to saturation in the presence of weak dissipation, and are characterized by a back-reaction on the imposed shear. Nu...
متن کاملSelf-Sustained Ionization and Vanishing Dead Zones in Protoplanetary Disks
We analyse the ionization state of the magnetohydrodynamically turbulent protoplanetary disks and propose a new mechanism of sustaining ionization. First, we show that in the quasi-steady state of turbulence driven by magnetorotational instability in a typical protoplanetary disk with dust grains the amount of energy dissipation should be sufficient for providing the ionization energy that is r...
متن کاملNumerical Study of the Magnetorotational Instability in Princeton MRI Experiment
In preparation for an experimental study of magnetorotational instability (MRI) in liquid metal, we present non-ideal axisymmetric magnetohydrodynamic simulations of the nonlinear evolution of MRI in the experimental geometry. The simulations adopt fully insulating boundary conditions. No-slip conditions are imposed at all boundaries. A clear linear phase is observed with reduced linear growth ...
متن کاملSaturation and Thermalization of the Magnetorotational Instability: Recurrent Channel Flows and Reconnections
The nonlinear evolution and the saturation mechanism of the magnetorotational instability (MRI) are investigated using three-dimensional resistive MHD simulations. A local shearing box is used for our numerical analysis and the simulations begin with a purely vertical magnetic field. We find that the magnetic stress in the nonlinear stage of the MRI is strongly fluctuating. The time evolution s...
متن کامل