The radial–azimuthal instability of accretion disk with anomalous viscosity

Abstract

The stability of the accretion disk is solved by numerical simulations when the radial and azimuthal perturbations are considered, where we adopt the anomalous viscosity model, which is close to real accretion disks. The results are discussed in the inner, intermediate, and outer regions of the accretion disk, respectively. With the increase of viscosity, α, the thermal mode and the viscous mode, as well as the acoustic modes, become more unstable in the disk dominated by radiation pressure (inner region). The instability is also influenced by the azimuthal perturbation wavenumber, n. With the increase of n, the thermal mode becomes more unstable, while the in-mode and out-mode become more stable no matter if the disk is dominated by radiation pressure or by gas pressure (intermediate and outer regions). There are many differences between our results and others’ results, especially in the inner region of the disk, when the anomalous viscosity is considered.