Changes between Version 14 and Version 15 of u/erica/AccretionModelingBlog


Ignore:
Timestamp:
03/20/18 20:03:07 (7 years ago)
Author:
Erica Kaminski
Comment:

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  • u/erica/AccretionModelingBlog

    v14 v15  
    66
    77||Lx=Ly=Lz|| 20 ||
     8||Mx=My=Mz || 64 ||
    89|| !MaxLevel (AMR) || 2 ||
    9 ||Mx=My=Mz || 64 ||
    1010|| Effective resolution (dx) || .15625 ||
    1111|| Sink dx = 4dx || .625 ||
     
    2525In 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.
    2626
    27 The IC's for this simulation include:
     27The following are the fiducial IC's used in the simulations (in computational units), unless otherwise noted:
    2828
    2929|| $C_{\infty}$ ||  1.291 ||
     
    3333|| $R_{BH}$ || 25.63 ||
    3434|| $\dot{M}$ || 2692.17  ||
     35||Lx=Ly=Lz|| 20 ||
     36||Mx=My=Mz || 64 ||
     37|| !MaxLevel (AMR) || 2 ||
     38|| Effective resolution (dx) || .15625 ||
    3539
    3640== Research Log: ==
     
    4852In other words, when $\gamma=5/3$ exactly, we have no accretion flow.
    4953
     54In addition to the Bondi/flow params cited in the top section of this page, the sim was setup using the following (in CU):
     55
    5056|| $\gamma$ || 1.66 ||
    5157|| $\lambda_{crit}$ || .2526 ||
    5258|| $R_{s}$ || .0128 ||
     59
     60Note, the sonic radius is not resolved by about a factor of 20 in this simulation, as seen when checking dx quoted above.
    5361
    5462The 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 $\lambda=\lambda_{crit}$).