Changes between Version 2 and Version 3 of u/massBElight


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Timestamp:
10/05/12 16:59:38 (12 years ago)
Author:
Erica Kaminski
Comment:

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  • u/massBElight

    v2 v3  
    11=== Tracking the mass that falls onto the BE sphere ===
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    3 I would like to calculate the mass that falls onto a BE sphere from the ambient over the course of a simulation. There may be a few ways to do this, but easiest may be what came to mind today: find M(t) using Visit's query option for total mass in box.
     3I would like to calculate the mass that falls onto a shell of dr=0.1RBe at r=Rbe from the ambient over the course of a simulation. There may be a few ways to do this, but easiest may be what came to mind today: find M(t) of the sphere with r=1.1Rbe, using Visit's query option for total mass in box.
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    55==== The method ====
    66
    7 First, I had to determine the right sum to use in visit. I see that the 'query' option had 2 sums: weighted and not. Additionally, the sum query is for the current plot. If that plot is a slice of the full simulation, the query will return only a sum of variables from that slice's mesh. 
     7First, I had to determine the right sum to use in Visit. I see that the 'query' option had 2 sums: weighted and not. Additionally, I found that the sum query is for the current plot. If that plot is a slice of the full simulation, the query will return only a sum of variables from that slice's mesh. Using my knowledge of the BE sphere's total mass from my simulation output --- that is, 151 solar mass, I calculated the mass of the ambient quite easily, given the ambient is of uniform density:
     8
     9{{{#!latex
     10Mamb = (30.4 - {4 \over 3}* \pi * Rbe^3^
     11}}}
     12
     13Putting this into computational units, I discovered that '''weighted variable sum''' was the correct query to get the total rho/cell (and hence mass) in the grid.
     14
     15The plan was to calculate M(t, 1.1Rbe) using the following formula:
     16
     17{{{#!latex
     18M(t) =
     19}}}
     20
     21