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A viscous instability in shearing laminar axisymmetric hydrodynamic flows around a gravitating center is described. In the linearized hydrodynamic equations written in the Boussinesq approximation with microscopic molecular transport…

High Energy Astrophysical Phenomena · Physics 2015-03-18 Nikolai Shakura , Konstantin Postnov

The non-linear hydrodynamic stability of thin, compressible, Keplerian disks is studied on the large two-dimensional compressible scale, using a high-order accuracy spectral method. We show that purely hydrodynamic perturbations, while…

Astrophysics · Physics 2009-10-31 Patrick Godon , Mario Livio

The origin of hydrodynamic turbulence in rotating shear flow is a long standing puzzle. Resolving it is especially important in astrophysics when the flow angular momentum profile is Keplerian which forms an accretion disk having negligible…

High Energy Astrophysical Phenomena · Physics 2015-05-27 Banibrata Mukhopadhyay , Kanak Saha

The linear stability of viscous Keplerian flow around a gravitating center is studied using the rheological granular fluid model. The linear rheological instability triggered by the interplay of the shear rheology and Keplerian differential…

Earth and Planetary Astrophysics · Physics 2017-07-25 Luka G. Poniatowski , Alexander G. Tevzadze

Warped astrophysical discs are usually treated as laminar viscous flows, which have anomalous properties when the disc is nearly Keplerian and the viscosity is small: fast horizontal shearing motions and large torques are generated, which…

Solar and Stellar Astrophysics · Physics 2015-06-15 Gordon I. Ogilvie , Henrik N. Latter

The mechanism of transition from laminar state to turbulent state in Keplerian disks is still unknown. The most popular version today is generation of turbulence due to magnetorotational instability (MRI). However magnetohydrodynamic…

High Energy Astrophysical Phenomena · Physics 2016-11-08 D. N. Razdoburdin

Hydrodynamic unstratified keplerian flows are known to be linearly stable at all Reynolds numbers, but may nevertheless become turbulent through nonlinear mechanisms. However, in the last ten years, conflicting points of view have appeared…

Astrophysics · Physics 2009-11-11 G. Lesur , P-Y. Longaretti

Laminar shear flows can display large non-modal perturbation growth, often through the lift-up mechansm, and can undergo subcritical transition to turbulence. The process is three-dimensional. Two-dimensional (2D) spanwise-independent…

Fluid Dynamics · Physics 2024-05-01 Sharath Jose

We employ a variety of numerical simulations in the local shearing box system to investigate in greater depth the local hydrodynamic stability of Keplerian differential rotation. In particular we explore the relationship of Keplerian shear…

Astrophysics · Physics 2009-10-31 John F. Hawley , Steven A. Balbus , Wayne F. Winters

The stability of nonaxisymmetric perturbations in differentially rotating astrophysical accretion disks is analyzed by fully incorporating the properties of shear flows. We verify the presence of discrete unstable eigenmodes with complex…

Astrophysics · Physics 2009-10-31 K. Noguchi , T. Tajima , R. Matsumoto

A three-dimensional nonlinear dynamo process is identified in rotating plane Couette flow in the Keplerian regime. It is analogous to the hydrodynamic self-sustaining process in non-rotating shear flows and relies on the magneto-rotational…

Astrophysics · Physics 2009-06-23 F. Rincon , G. I. Ogilvie , M. R. E. Proctor

The dynamics of small global perturbations in the form of linear combination of a finite number of non-axisymmetric eigenmodes is studied in two-dimensional approximation. The background flow is assumed to be an axisymmetric perfect fluid…

Astrophysics · Physics 2008-10-15 V. V. Zhuravlev , N. I. Shakura

It is now established that subcritical mechanisms play a crucial role in the transition to turbulence of non-rotating plane shear flows. The role of these mechanisms in rotating channel flow is examined here in the linear and nonlinear…

Fluid Dynamics · Physics 2024-05-01 Sharath Jose , Vishnu Kuzhimparampil , Benoît Pier , Rama Govindarajan

We find and investigate via numerical simulations self-sustained two-dimensional turbulence in a magnetohydrodynamic flow with a maximally simple configuration: plane, noninflectional (with a constant shear of velocity) and threaded by a…

Plasma Physics · Physics 2014-10-01 G. R. Mamatsashvili , D. Z. Gogichaishvili , G. D. Chagelishvili , W. Horton

We study linear transient dynamics in a thin Keplerian disc employing a method based on variational formulation of optimisation problem. It is shown that in a shearing sheet approximation due to a prominent excitation of density waves by…

High Energy Astrophysical Phenomena · Physics 2015-06-19 V. V. Zhuravlev , D. N. Razdoburdin

We report a direct-numerical-simulation study of Taylor-Couette flow in the quasi-Keplerian regime at shear Reynolds numbers up to $\mathcal{O}(10^5)$. Quasi-Keplerian rotating flow has been investigated for decades as a simplified model…

Fluid Dynamics · Physics 2017-11-21 Liang Shi , Bjoern Hof , Markus Rampp , Marc Avila

Enhanced angular momentum transfer through the boundary layer near the surface of weakly magnetised accreting star is required in order to explain the observed accretion timescales in low-mass X-ray binaries, cataclysmic variables or young…

High Energy Astrophysical Phenomena · Physics 2018-11-07 V. V. Zhuravlev , D. N. Razdoburdin

Flow nonnormality induced linear transient phenomena in thin self-gravitating astrophysical discs are studied in the shearing sheet approximation. The considered system includes two modes of perturbations: vortex and (spiral density) wave.…

Astrophysics · Physics 2009-11-13 G. R. Mamatsashvili , G. D. Chagelishvili

Subcritical transition to turbulence in Keplerian accretion disks is still a controversial issue and some theoretical progress is required in order to determine whether or not this scenario provides a plausible explanation for the origin of…

Astrophysics · Physics 2009-11-11 F. Rincon , G. I. Ogilvie , C. Cossu

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