[yt-users] Shock Finding

[Britton Smith]

Hi Yuan,

Sam's shock-finder for Enzo works quite well.  He created some tools that I
don't think he would mind me sharing on his behalf.  They haven't been
updated in two years, so they will likely only work with yt-2.x unless you
update them.  They will create shock mach number fields that you can use in
yt.  Anyway, they are here:
https://bitbucket.org/samskillman/shock_in_a_box/

Britton

On Tue, Jun 23, 2015 at 5:06 PM, Michael Zingale <
michael.zingale at stonybrook.edu> wrote:

> that should have read: "to separate shocks from contacts"
>
> On Tue, Jun 23, 2015 at 12:04 PM, Michael Zingale <
> michael.zingale at stonybrook.edu> wrote:
>
>> I don't have yt code, but I agree that this would be a useful standard
>> derived field to add.  As for the methodology, the shock detection
>> algorithm that is used in a lot of codes looks for regions where there is
>> compression and a pressure jump (to separate shocks from rarefactions).
>> Most PPM or similar hydro codes (even those that are not directionally
>> split) will do this check in 1-d when determining whether to apply
>> flattening to shocks (to prevent their self-steepening from making them too
>> steep), and then look in all directions to figure out if a zone should be
>> flattened.  You want to do a single multi-d shock detection, which will
>> mean computing the velocity divergence and the pressure jump in the normal
>> direction.  Here's the code we use in Castro which inherits some ideas from
>> other codes (Flash, and the ppm papers).  Look for the subroutine shock().
>>
>>
>> https://github.com/BoxLib-Codes/Castro/blob/master/Source/Src_3d/riemann_3d.f90
>>
>>
>>
>>
>> On Tue, Jun 23, 2015 at 11:51 AM, Yuan Li <yuan at astro.columbia.edu>
>> wrote:
>>
>>> Dear all,
>>>
>>> I am trying to figure out a way to mask out cells that contain shocks.
>>> One way I can think of is to create a derived field by identifying shocks.
>>> It seems that there are different ways of finding shocks: Enzo has a
>>> refinement criterion (refine by shocks) and there is also shock finding
>>> written by Sam.
>>>
>>> Has anybody tried to find shocks using yt? I would appreciate it if you
>>> would like to share your code/experience/advice. Thank you!
>>>
>>> Yuan
>>>
>>> _______________________________________________
>>> yt-users mailing list
>>> yt-users at lists.spacepope.org
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>>>
>>>
>>
>>
>> --
>> Michael Zingale
>> Associate Professor
>>
>> Dept. of Physics & Astronomy • Stony Brook University • Stony Brook, NY
>> 11794-3800
>> *phone*:  631-632-8225
>> *e-mail*: Michael.Zingale at stonybrook.edu
>> *web*: http://www.astro.sunysb.edu/mzingale
>>
>
>
>
> --
> Michael Zingale
> Associate Professor
>
> Dept. of Physics & Astronomy • Stony Brook University • Stony Brook, NY
> 11794-3800
> *phone*:  631-632-8225
> *e-mail*: Michael.Zingale at stonybrook.edu
> *web*: http://www.astro.sunysb.edu/mzingale
>
> _______________________________________________
> yt-users mailing list
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>
>
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