[Nek5000-users] Post-Processing from avg_all files using Nek / Visit

[nek5000-users at lists.mcs.anl.gov]

Hi Shriram,

the rm2 file has uv vw wu

Look for "outpost" in navier5.f, which is where the avg_all()
routine is found.   Note that, because of space limitations,
not _all_ of the <uT> <vT> <wT> fields are computed/stored....
but these clearly could be added for someone interested in 
turbulent Nu computations.

Cheers,

Paul




On Fri, 31 Dec 2010, nek5000-users at lists.mcs.anl.gov wrote:

> Hi Paul,
>
> Thanks. I did set up a python script (thanks to Hank) in VisIt to do the
> interpolation and o/p as txt file. Does rmsblah.f0000 file have the other
> components of Reynolds stress viz. <uv>, <vw>, <wu> ? Yes, we have a routine
> for getting the fluctuating components from nek and outside of it as well.
>
> Regards
> Shriram
>
>
> On 31 December 2010 09:27, <nek5000-users at lists.mcs.anl.gov> wrote:
>
>>
>> Hi Shriram,
>>
>> I see that Hank answered some of your questions already.
>>
>> If we define u = <u> + u' then we have
>>
>> <u'>^2 = <u^2> - <u>^2
>>
>> with <u^2> stored in rms and <u> stored in avg.   (Similar
>> forms exist for the cross terms.)   postx can load the
>> rms and avg files to give you <u'>^2 -- but not yet with the
>> .f0000 format.
>>
>> Another common approach is to manipulate these by loading all the avg files
>> inside the solver itself.   We can set up an
>> example that illustrates this.    At that point, you could
>> also interpolate the output onto a finer mesh before passing
>> to visit.
>>
>> Paul
>>
>>
>>
>>
>> On Thu, 30 Dec 2010, nek5000-users at lists.mcs.anl.gov wrote:
>>
>>  Hi,
>>>
>>> I would like to post-process quantities from avg_all files (rms, rm2,
>>> avg).
>>> Particularly I am looking at line plots (mainly) or contours on a plane. I
>>> had a question regarding the approach that I might be taking..
>>>
>>> If I load the files, say rmsblah.f0000* into nek using the load subroutine
>>> and fill the ux,uy,uz arrays with that of <u^2>, <v^2>, <w^2> and call
>>> hpts(), how would the interpolation work ? Would it interpolate <u^2> with
>>> the interpolation that is used for velocities ?. The other option would be
>>> to do a line plot from Visit and export it to a text file. Also, I am not
>>> sure how Visit interpolates. Which is more likely to be accurate ?
>>>
>>> Regards
>>> Shriram
>>>
>>>
>>
>> Z_
>>
>>
>> kk
>>
>> kk
>> http://cuireadhchunceoil.ie/index.php?option=com_content&view=article&id=58
>>
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>