Changes between Version 14 and Version 15 of u/erica/AccretionModelingBlog
- Timestamp:
- 03/20/18 20:03:07 (7 years ago)
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u/erica/AccretionModelingBlog
v14 v15 6 6 7 7 ||Lx=Ly=Lz|| 20 || 8 ||Mx=My=Mz || 64 || 8 9 || !MaxLevel (AMR) || 2 || 9 ||Mx=My=Mz || 64 ||10 10 || Effective resolution (dx) || .15625 || 11 11 || Sink dx = 4dx || .625 || … … 25 25 In the above, $\lambda$ is a numerical coefficient which controls the strength of the accretion flow. At its critical value, $\lambda=\lambda_{crit}$, $\dot{M}$ is strongest. In the code, $\lambda_{crit}$ is solved for using Eqn. 18 in Bondi's paper. 26 26 27 The IC's for this simulation include:27 The following are the fiducial IC's used in the simulations (in computational units), unless otherwise noted: 28 28 29 29 || $C_{\infty}$ || 1.291 || … … 33 33 || $R_{BH}$ || 25.63 || 34 34 || $\dot{M}$ || 2692.17 || 35 ||Lx=Ly=Lz|| 20 || 36 ||Mx=My=Mz || 64 || 37 || !MaxLevel (AMR) || 2 || 38 || Effective resolution (dx) || .15625 || 35 39 36 40 == Research Log: == … … 48 52 In other words, when $\gamma=5/3$ exactly, we have no accretion flow. 49 53 54 In addition to the Bondi/flow params cited in the top section of this page, the sim was setup using the following (in CU): 55 50 56 || $\gamma$ || 1.66 || 51 57 || $\lambda_{crit}$ || .2526 || 52 58 || $R_{s}$ || .0128 || 59 60 Note, the sonic radius is not resolved by about a factor of 20 in this simulation, as seen when checking dx quoted above. 53 61 54 62 The simulation setup reproduces the correct nondimensional profiles. Here's a comparison of the t=0 nondimensional density and velocity profiles astrobear calculates for the bondi module (left), compared to the Bondi solutions for $\gamma=5/3$ (curves II and III for the case of $\lambda=\lambda_{crit}$).