Abstract

We investigate the possible origin of the unstablemass-outflows froma low angularmomentumthick accretion flow around stationary black hole using 2D time-dependent hydrodynamical simulation. When the flow is advection dominated, a torus disc is formed in the vicinity of the black hole. At the inner edge of the torus, a series of hot blobs is intermittently developed which grow up along the outer surface of the torus and eventually causes the irregular modulation of luminosity and the mass-outflow rate. We point out that the unstable behavior of the mass-outflow perhaps results due to the existence of Kelvin-Helmholtz instability in the inner region of the flow.