Linear coupling of modes in 2D radially stratified astrophysical discs

Abstract

We investigate mode coupling in a two dimensional compressible disc with radial stratification and differential rotation. We employ the global radial scaling of linear perturbations and study the linear modes in the local shearing sheet approximation. We employ a three-mode formalism and study the vorticity (W), entropy (S) and compressional (P) modes and their coupling properties. The system exhibits asymmetric three-mode coupling: these include mutual coupling of S and P-modes, S and W-modes, and asymmetric coupling between the W and P-modes. P-mode perturbations are able to generate potential vorticity through indirect three-mode coupling. This process indicates that compressional perturbations can lead to the development of vortical structures and influence the dynamics of radially stratified hydrodynamic accretion and protoplanetary discs.

10 pages, 10 figures, MNRAS (accepted)

References in corpus (23)

• Rossby Wave Instability of Keplerian Accretion Disks
• Turbulence in Accretion Disks. Vorticity Generation and Angular Momentum Transport via the Global Baroclinic Instability
• Magnetorotational Instability in Protoplanetary Disks. II. Ionization State and Unstable Regions
• Rossby Wave Instability of Thin Accretion Disks -- II. Detailed Linear Theory
• The ionization fraction in alpha-models of protoplanetary disks
• The excitation of spiral density waves through turbulent fluctuations in accretion discs II: Numerical Simulations with MRI driven turbulence
• On the origin of episodic accretion in Dwarf Novae
• Three-Dimensional Vortices in Stratified Protoplanetary Disks
• Millimeter imaging of HD 163296: probing the disk structure and kinematics
• Baroclinic Vorticity Production in Protoplanetary Disks; Part I: Vortex Formation
• Baroclinic Vorticity Production in Protoplanetary Disks; Part II: Vortex Growth and Longevity
• The Global Baroclinic Instability in Accretion Disks. II: Local Linear Analysis
• The excitation of spiral density waves through turbulent fluctuations in accretion discs I: WKBJ theory
• Vortices in Thin, Compressible, Unmagnetized Disks
• Three Dimensional Compressible Hydrodynamic Simulations of Vortices in Disks
• Linear Theory of Thin, Radially-Stratified Disks
• Spiral density wave generation by vortices in Keplerian flows
• Spatially resolved spectroscopy of planetary nebulae and their halos I. Five galactic disk objects
• Hydrodynamic stability and mode coupling in Keplerian flows: local strato-rotational analysis
• Nonlinear Stability of Thin, Radially-Stratified Disks
• Transient growth and coupling of vortex and wave modes in self-gravitating gaseous discs
• Stability and nonlinear adjustment of vortices in Keplerian flows
• Nonaxisymmetric stability in the shearing sheet approximation

Cited by in corpus (9)

• The baroclinic instability in the context of layered accretion. Self-sustained vortices and their magnetic stability in local compressible unstratified models of protoplanetary disks
• A Parameter Study for Baroclinic Vortex Amplification
• Revisiting linear dynamics of non-axisymmetric perturbations in weakly magnetized accretion discs
• Transient dynamics of perturbations in astrophysical disks
• Mechanism for flow generation/acceleration in dense degenerate stellar atmospheres
• Transient growth of perturbations on scales beyond the accretion disc thickness
• Excitation of spiral density waves by convection in accretion discs
• An optimal transient growth of small perturbations in thin gaseous discs
• Visco-rotational shear instability of Keplerian granular flows