[Nek5000-users] Add/subtract 1d-mean profile

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

Jan,

For what you want, I would do it inside nek, but it could
also be done in VisIt or in postnek by sampling the field
along many z-lines and then averaging these together.

What is the size (E,N) of your data?

Regards,

Paul


On Fri, 9 Mar 2012, nek5000-users at lists.mcs.anl.gov wrote:

> Hi Aleks,
>
> thank you for posting your routines. They are certainly very useful!
> But my point is to find an easy and quick way to check a single velocity
> field. That can usually be done by taking the means over the full box and
> subtracting them (as described in the first mail) from the instantaneous
> field.
> I don't wanna do my full postprocessing that way. It's just to have a quick
> look on the data (in particular the fluctuations)...
> Do you think that is possible?
>
> Thanks!
> Jan F.
>
> Am 9. März 2012 15:34 schrieb <nek5000-users at lists.mcs.anl.gov>:
>
>> Hi Jan,
>>
>> Here are routines that I sometimes use that call avg_all for the list of a
>> dump binary files given in a.list
>>
>> http://www.mcs.anl.gov/~obabko/avg_fld.usr
>>
>> Use
>>
>>     call avg_fld_all
>>
>> in post-processing mode of Nek5000 (nsteps=0 in .rea) with a created
>> a.list file of your binary .f files (for .fld files uncomment line with p66
>> & p67 = 4)
>>
>> Best.
>> Aleks
>>
>>
>>
>> ----- Original Message -----
>> From: nek5000-users at lists.mcs.anl.gov
>> To: nek5000-users at lists.mcs.anl.gov
>> Sent: Wednesday, March 7, 2012 4:10:44 AM
>> Subject: [Nek5000-users] Add/subtract 1d-mean profile
>>
>>
>> Hi NEKs,
>>
>> I'm new to NEK and as a first exercise I'm calculating DNS of turbulent
>> channel flow. So far everything is fine and works as is should.
>>
>> Now i wanna do some postprocessing with the (binary) files I dumped out.
>> Let's say I wanna look at a single file:
>>
>> Is it possible to calc the 1d mean of u over the whole channel domain (for
>> example with "call planar_average_s") then take this 1d mean profile and
>> subtract it from u at every point to get u' (=> u'(i,j,k,e) = u(i,j,k,e) -
>> <u>(j))?
>>
>> As I didn't dump the averages with "avg_all()" the hint given in
>> https://lists.mcs.anl.gov/mailman/htdig/nek5000-users/2010-May/000451.htmlin this case is not applicable.
>>
>> Thanks!
>> Jan Frielinghausen
>>
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