Local numerical simulations of warped discs

Abstract

We study the hydrodynamical stability of the laminar flows associated with warped astrophysical discs using numerical simulations of warped shearing boxes. We recover linear growth rates reported previously due to a parametric resonance of inertial waves, and show that the nonlinear saturated state can significantly reduce the laminar flows, meaning that the warp would evolve on much longer time scales than would be concluded from the internal torques due to these laminar flows. Towards larger warp amplitudes, we find first of all a reversal of angular momentum flux, indicating that the mass distribution would evolve in an anti-diffusive manner, and second that the linear growth rates disappear, possibly because of the very strong shear in the laminar flows in this regime. For discs with small enough viscosity, a nonlinear state can still be found when linear growth rates are absent by introducing a large enough perturbation, either by starting from a nonlinear state obtained at smaller warp amplitude, or by starting from a state with no laminar flows.

17 pages, 17 figures, accepted for publication in MNRAS

References in corpus (9)

• Global General Relativistic MHD Simulation of a Tilted Black-Hole Accretion Disk
• Warp diffusion in accretion discs: a numerical investigation
• Interaction between massive planets on inclined orbits and circumstellar discs
• Local and global dynamics of eccentric astrophysical discs
• Instability of warped discs
• Hydrodynamic instability in eccentric astrophysical discs
• Non-linear hydrodynamic instability and turbulence in eccentric astrophysical discs with vertical structure
• A local model of warped magnetised accretion discs
• Multidimensional upwind hydrodynamics on unstructured meshes using Graphics Processing Units I. Two-dimensional uniform meshes

Cited by in corpus (13)

• Radiation Transport Two-Temperature GRMHD Simulations of Warped Accretion Disks
• Parametric instability in a free evolving warped protoplanetary disc
• Constraining the Circumbinary Disk Tilt in the KH 15D system
• HFQPOs and discoseismic mode excitation in eccentric, relativistic discs. II. Magnetohydrodynamic simulations
• On the dynamics of low-viscosity warped discs around black holes
• On the equations of warped disc dynamics
• HFQPOs and discoseismic mode excitation in eccentric, relativistic discs. I. Hydrodynamic simulations
• Parametric instability in warped astrophysical discs: growth, saturation and feedback
• Hydrodynamics of warps in the local model of astrophysical discs
• The Interplay of Parametric and Magnetorotational Instabilities in Oscillatory Shear Flows
• A Local Model for the Spherical Collapse/Expansion Problem
• Disc breaking and parametric instability in warped accretion discs
• Nonlinear behaviour of warped discs around a central object with a quadrupole moment