Bondi Accretion

3/18/2018

Am working on a 3D simulation of Bondi Flow onto a central sink particle and studying the accretion properties using the Krumholz accretion algorithm.

The setup has the following parameters (in computational units):

Lx=Ly=Lz	20
MaxLevel (AMR)	2
Mx=My=Mz	64
Effective resolution (dx)	.15625
Sink dx = 4dx	.625

The following parameters are used for calculating the Bondi Flow onto the particle:

\gamma	1.66
\lambda_{crit}

From Bondi (1952) we have the following quantities (in order: Bondi radius, accretion rate, sonic radius, nondimensional density and velocity):

R_{BH}

In addition, the Bondi solution requires a numerical constant, \lambda, which controls the strength of the accretion flow. At its critical value, \lambda=\lambda_{crit}, \dot{M} is strongest. The case of \gamma=5/3 flow is an extreme limit for the solution space. When

, . In the code, is found in a lookup table and is set as:

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