Changes between Version 35 and Version 36 of u/erica/AccretionModelingBlog


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Timestamp:
03/25/18 22:54:51 (7 years ago)
Author:
Erica Kaminski
Comment:

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  • u/erica/AccretionModelingBlog

    v35 v36  
    6161Note -- I did this lineout from the center of the first zone in the octant surrounding the sink, to the zone center at the edge of the boundary. Aside from doing a spherical average over shells, I think this will provide the most accurate results from Visit (rather than along cell boundaries, which I am not sure how Visit interpolates..)
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    63 Calculating the mass flux through spherical shells surrounding the sink seems to agree well with the predicted value of $\dot{M}_{BH}=8646.9$. I tried at 3 different radii: $r=5<R_s$, $r=7>R_s$, $r=25>OBS$, where $OBS$ is the spherical boundary in the grid beyond which the Bondi solution is pasted into cells:
     63Calculating the mass flux through spherical shells surrounding the sink seems to agree well with the predicted value of $\dot{M}_{BH}=8646.9$. I tried at 3 different radii: $r=5<R_s$, $r=8>R_s$, $r=25>OBS$, where $OBS$ is the spherical boundary in the grid beyond which the Bondi solution is pasted into cells:
    6464
    6565[[Image(mdot_comp_gamma1pt4.png, 35%)]]
     
    8282[[Image(press_zoomed_gam1pt4.png, 35%)]]
    8383
    84 It is also notable how symmetric the pressure is within the kernel (in this plane as well as the other coordinate planes). A similar plot of density:
     84It is also notable how symmetric the pressure is within the kernel (in this plane as well as the other coordinate planes). The relative orientation of the velocity vectors is also interesting. Despite the appearance of a subsonic, post-shock flow field by frame 1, within the kernel (central 8x8 zones) the velocity vectors point inward to the sink particle ''predominantly'' along the coordinate axes.. This is so much so it is somewhat reminiscent of a convective instability.. A similar plot of density:
    8585
    8686[[Image(rho_zoomed_gam1pt4.png, 35%)]]
     
    9090[[Image(plane_comp_gam1pt4.png, 35%)]]
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    92 The mass flux through a shell with $r=r_{acc}$, as well as onto the particle is much lower (and variable) than the predicted $\dot{M}$:
     92The mass flux through a shell with $r=r_{acc}$, as well as onto the particle is much lower (and variable) than the predicted $\dot{M}$ (note the last time query corresponds to the 0th frame, and the first the 8th -- the points between are equally spaced between these):
    9393
    9494[[Image(mdot_sink_gam1pt4.png, 35%)]]
    9595
    96 A [attachment:press_sonicrad.gif​ movie] of the pressure with overlaid velocity vectors and contours of the sonic surfaces shows the generation of multiple shock layers, both at the surface of the kernel, as well as inside the kernel.
     96A [attachment:press_sonicrad.gif​ movie of the pressure with overlaid velocity vectors and contours of the sonic surfaces] shows the generation of multiple shock layers, both at the surface of the kernel, as well as inside the kernel.
    9797
    98 The same [attachment:press_sonicrad_zoomout.gif​ movie], but zoomed out, shows that the sonic radius of the Bondi solution is correctly located at $R_s=6$, and doesn't move over time.
     98The [attachment:press_sonicrad_zoomout.gif​ same movie, but zoomed out], shows that the sonic radius of the Bondi solution is correctly located at $R_s=6$, and doesn't move over time.
    9999
    100 Finally, we have lineout movies of [attachment:press_lineout.gif​ pressure], [attachment:rho_lineout.gif​ density], and [attachment:vrad_lineout.gif​ vrad]. As these movies show, the Bondi solution is unaltered beyond $r>20$, as to be expected from the boundary conditions of the sim. Also surprising, despite the density falling below its initial value in the kernel (due to accretion), the pressure spikes there seemingly artificially (rather than due to a build of material in the kernel).
     100Finally, we have lineout movies of [attachment:press_lineout.gif​ pressure], [attachment:rho_lineout.gif​ density], and [attachment:vrad_lineout.gif​ vrad]. As these movies show, the Bondi solution is unaltered beyond $r>20$, as to be expected from the boundary conditions of the sim. Surprisingly, however, is that despite the density falling below its initial value in the kernel (due to accretion), the pressure spikes there seemingly artificially (rather than due to a build of material in the kernel).
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    102102