On the Maximal Value of the Turbulent alpha-Parameter in Accretion Discs

Abstract

In this short paper we show that making turbulence two- rather than three-dimensional may increase effective turbulent viscosity by about 40%. Dimensionless hydrodynamical viscosity parameter up to α\_{max} = 0.25 M_t^2 may be obtained in this approach, that is in better agreement with the observational data on non-stationary accretion than the values obtained in numerical simulations. However, the α-parameter values known from observations are still several times higher.

4 pages, accepted to Astronomische Nachrichten

References in corpus (9)

• Accretion disc viscosity: how big is alpha?
• Hydrodynamic turbulence cannot transport angular momentum effectively in astrophysical disks
• Testing Accretion Disk Theory in Black Hole X-ray Binaries
• On the Stability of Elliptical Vortices in Accretion Discs
• Three Dimensional Compressible Hydrodynamic Simulations of Vortices in Disks
• The Dependence of Spectral State Transition and Disk Truncation on Viscosity Parameter $α
• Modeling of non-stationary accretion disks in X-ray novae A 0620-00 and GRS 1124-68 during outburst
• Formation, Survival, and Destruction of Vortices in Accretion Disks
• Stability and nonlinear adjustment of vortices in Keplerian flows