On the role of initial and boundary conditions in numerical simulations of accretion flows

Abstract

We study the effects of initial and boundary conditions, taking two-dimensional hydrodynamical numerical simulations of hot accretion flow as an example. The initial conditions considered include a rotating torus, a solution expanded from the one-dimensional global solution of hot accretion flows, injected gas with various angular momentum distributions, and the gas from a large-scale numerical simulation. Special attention is paid to the radial profiles of the mass accretion rate and density. Both can be described by a power-law function, $\dot{M}\propto r^s$ and $\rho \propto r^{-p}$. We find that if the angular momentum is not very low, the value of $s$ is not sensitive to the initial condition and lies within a narrow range, $0.47\la s \la 0.55$. However, the value of $p$ is more sensitive to the initial condition and lies in the range $0.48\la p \la 0.8$. The diversity of the density profile is because different initial conditions give different radial profiles of radial velocity due to the different angular momentum of the initial conditions. When the angular momentum of the accretion flow is very low, the inflow rate is constant with radius. Taking the torus model as an example, we have also investigated the effects of inner and outer boundary conditions by considering the widely adopted "outflow" boundary condition and the "mass flux conservation" condition. We find that the results are not sensitive to these two boundary conditions.

10 pages, 15 figures, accepted by MNRAS

References in corpus (10)

• The Two Young Star Disks in the Central Parsec of the Galaxy: Properties, Dynamics and Formation
• Advection-Dominated Accretion and the Black Hole Event Horizon
• Numerical Simulation of Hot Accretion Flows (II): Nature, Origin, and Properties of Outflow and Their Possible Observational Applications
• Numerical Simulation of Hot Accretion Flows (I): A Large Radial Dynamical Range and the Density Profile of Accretion Flow
• Stellar and wind properties of massive stars in the central parsec of the Galaxy
• Galactic Centre stellar winds and Sgr A* accretion
• Feedback from central black holes in elliptical galaxies. I: models with either radiative or mechanical feedback but not both
• Variable accretion and emission from the stellar winds in the Galactic centre
• Rotating Accretion Flows: From Infinity to the Black Hole
• Accretion of cool stellar winds on Sgr A*: another puzzle of the Galactic Centre?

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