[Nek5000-users] hpts and pressure

Tue Jun 14 13:45:19 CDT 2011

Why not after the pressure solve every time step? I don't think it
will add much.
-Stefan

On 6/14/11, nek5000-users at lists.mcs.anl.gov
<nek5000-users at lists.mcs.anl.gov> wrote:
>
> Josh, Stefan,
>
> Correct... we should just add the map to the hpts
> routine.   Maybe Katie can take care of this.
>
> Thanks for raising this issue!
>
> Paul
>
>
> On Tue, 14 Jun 2011, nek5000-users at lists.mcs.anl.gov wrote:
>
>> Hi
>>
>> You are right, the pressure is not mapped automatically. This issue
>> was already discussed in
>> https://lists.mcs.anl.gov/mailman/htdig/nek5000-users/2010-May/000584.html.
>> At the moment there is only a trigger to map the pressure in case we
>> are dumping a field file
>>
>> @Paul: I am not sure where we should trigger the pressure mapping but
>> the way it's implement now is error prone.
>>
>> -Stefan
>>
>> On 6/14/11, nek5000-users at lists.mcs.anl.gov
>> <nek5000-users at lists.mcs.anl.gov> wrote:
>>> Hello,
>>>
>>> It appears my hypothesis was correct.  I post the following for
>>> reference to any users who run into the same issue in the future (and
>>> I apologize in advance if this question has already been answered
>>> before, I didn't see anything in my search, but that doesn't mean it
>>> wasn't there).
>>>
>>> 1)  I included the following in the variable declarations of userchk()
>>>
>>>       common /scrcg/ pm1(lx1,ly1,lz1,lelv)  ! Mapped pressure
>>>       real pa(lx1,ly2,lz2), pb(lx1,ly1,lz2) ! Working arrays for mappr
>>>
>>> 2) Then, before I call hpts, I call mappr
>>>
>>>       if (mod(istep,10).eq.0) then   ! Only call this every 10th step
>>>          call mappr(pm1,pr,pa,pb)   ! Map pressure first
>>>          call hpts
>>>       endif
>>>
>>> For my case, I didn't want to call hpts every time step to prevent
>>> hpts.out from becoming too large.
>>>
>>> I haven't run this for too long, but on a preliminary basis the
>>> results look good.  It seems that the scrcg common block must be
>>> included in userchk for this to work, as pm1 isn't a part of any of
>>> the standard "include" files.
>>>
>>> Developers and other users, feel free to chime in if there is a more
>>> efficient or elegant solution to this problem.
>>>
>>> Thanks,
>>>
>>> Josh
>>>
>>> On Mon, Jun 13, 2011 at 6:42 PM,  <nek5000-users at lists.mcs.anl.gov>
>>> wrote:
>>>> Hi Josh,
>>>>
>>>> Yes, it seems to me that either htps() needs modification for Pn-Pn-2
>>>> pressure points or pr() should be mapped to pm1() before calling htps()
>>>> as
>>>> you suggested -- something along the lines for .not.ifsplit in
>>>> prepot.f:219
>>>>
>>>>         if (ifsplit) then
>>>>            call copy(pm1,pr,ntot1)
>>>>         else
>>>>            do 1000 e=1,nelv
>>>>               call mxm (ixm21,nx1,pr(1,1,1,e),nx2,pa(1,1,1),nyz2)
>>>>               do 100 iz=1,nz2
>>>>                  call mxm (pa(1,1,iz),nx1,iytm21,ny2,pb(1,1,iz),ny1)
>>>>  100          continue
>>>>               call mxm (pb(1,1,1),nxy1,iztm21,nz2,pm1(1,1,1,e),nz1)
>>>>  1000       continue
>>>>         endif
>>>>
>>>> Best,
>>>> Aleks
>>>>
>>>>
>>>> ----- Original Message -----
>>>> From: nek5000-users at lists.mcs.anl.gov
>>>> To: "nek5000-users" <nek5000-users at lists.mcs.anl.gov>
>>>> Sent: Monday, June 13, 2011 5:29:50 PM
>>>> Subject: [Nek5000-users] hpts and pressure
>>>>
>>>> Hello Neks,
>>>>
>>>> I am trying to output pressure data at various points using the hpts
>>>> routine.
>>>>
>>>> The values that are output for the first time step look ok, but all
>>>> subsequent time steps seem to give garbage (i.e. the pressures given
>>>> in hpts.out are way different that what is given by visualizing
>>>> pressure in VisIt).  I know previously that this was an issue for
>>>> someone and it was thought that passive scalars may be messing the
>>>> hpts output up, but in my case I don't output temperature or pressure.
>>>>
>>>> I looked at the hpts routine and noticed that it uses pm1 when it is
>>>> stacking the field variables into the working array.  Since I am using
>>>> a Pn-Pn-2 formulation for my case, do I need to use the mappr
>>>> subroutine in my usrchk to map the pressure from mesh 2 to mesh 1
>>>> before calling hpts()?
>>>>
>>>> I'm assuming the issue arises because I am calling hpts more
>>>> frequently than I am outputing field files, and thus perhaps pm1 isn't
>>>> properly being updated (or perhaps it may have already been
>>>> destroyed).
>>>>
>>>> Thanks,
>>>>
>>>> --
>>>> Josh Camp
>>>>
>>>> "All that is necessary for the triumph of evil is that good men do
>>>> nothing" -- Edmund Burke
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>>>
>>>
>>>
>>> --
>>> Josh Camp
>>>
>>> "All that is necessary for the triumph of evil is that good men do
>>> nothing" -- Edmund Burke
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