摘要
We explore the time evolution of radiatively-inefficient accretion flows. Since these types of accretion flows are convectively unstable, we also study the ef- fects of convection in the present model. The effects of convection are applied to equations describing angular momentum and energy. In analogy to the traditional c^- prescription, we introduce the convection parameter c^e to study the influences of con- vection on physical quantities. The model is studied in two cases： the transport of angular momentum due to convection inward and outward. We found the physical variables are sensitive to the parameter C^c and are also dependent on the direction of angular momentum that is transported by convection. As for angular momentum transfer inward, the accretion flow can be convectively dominated and radial infall velocity becomes zero. Moreover, we found the radial dependence of the density and radial velocity takes an intermediate place between steady state radiatively-inefficient accretion flow and steady state advection-dominated accretion flow. This property is in accord with direct numerical simulation of radiatively-inefficient accretion flows.
We explore the time evolution of radiatively-inefficient accretion flows. Since these types of accretion flows are convectively unstable, we also study the ef- fects of convection in the present model. The effects of convection are applied to equations describing angular momentum and energy. In analogy to the traditional c^- prescription, we introduce the convection parameter c^e to study the influences of con- vection on physical quantities. The model is studied in two cases： the transport of angular momentum due to convection inward and outward. We found the physical variables are sensitive to the parameter C^c and are also dependent on the direction of angular momentum that is transported by convection. As for angular momentum transfer inward, the accretion flow can be convectively dominated and radial infall velocity becomes zero. Moreover, we found the radial dependence of the density and radial velocity takes an intermediate place between steady state radiatively-inefficient accretion flow and steady state advection-dominated accretion flow. This property is in accord with direct numerical simulation of radiatively-inefficient accretion flows.
