[Nek5000-users] Restart with geometry changes

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

Hi David,

Nek does the following:

Sets geometry

Reads I.C.s

If you .fld file contains geometry, this supersedes
the geometry that has been set unless you say otherwise.

Paul

On Fri, 11 Mar 2011, nek5000-users at lists.mcs.anl.gov wrote:

> Hi Paul,
>
> This post is making me wonder if I understand how restarting works.  If I
> have some geometry in my .rea file, and I restart from a .fld file with
> different geometry, which geometry takes precedence?  I had been assuming
> that nek interpolated the old data onto the mesh in the .rea file.  And is
> the answer affected by whether or not the .fld file contains geometry data?
> I think only my fld01 files contain that.
>
> Best,
>
> David
>
> On Fri, Mar 11, 2011 at 9:41 AM, <nek5000-users at lists.mcs.anl.gov> wrote:
>
>>
>> Markus,
>>
>> If you're using .fld files, you can simply modify your .rea file:
>>
>> :
>> :
>>            1 PRESOLVE/RESTART OPTIONS  *****
>> my_old.fld01  U P T time=0
>> :
>> :
>> :
>>
>>
>> which tells nek to take _only_ U P T and from the .fld
>> file (assuming they are present), and to not take anything
>> else.   Also, it tells it to reset time to 0 at the start
>> of this calculation.   Note that if you have, say,
>>
>>            2 PRESOLVE/RESTART OPTIONS  *****
>> my_old.fld01  U P T time=0
>> my_old.fld02    P T
>>
>>
>> it would take U from fld01 and P, T, and time from fld02.
>>
>>
>> I don't believe we have this level of support in the .f0000
>> format yet, but I can possibly put someone on it.
>>
>> In your case (assuming you're using .f0000 format), you can
>> instead do the following in usrdat2 (by which point nek
>> knows the geometry, but has not yet read initial conditions):
>>
>>
>> c-----------------------------------------------------------------------
>>      subroutine usrdat2
>>      include 'SIZE'
>>      include 'TOTAL'
>>      parameter (ltt=lx1*ly1*lz1*lelt)
>>      common /cmygeom/ xmo(llt),ymo(llt),zmo(llt)
>>
>>      call opcopy(xmo,ymo,zmo,xm1,ym1,zm1)  ! Preserve my geometry
>>
>>      return
>>      end
>> c-----------------------------------------------------------------------
>>      subroutine usrchk
>>      include 'SIZE'
>>      include 'TOTAL'
>>      parameter (ltt=lx1*ly1*lz1*lelt)
>>      common /cmygeom/ xmo(llt),ymo(llt),zmo(llt)
>>
>>      call opcopy(xm1,ym1,zm1,xmo,ymo,zmo)  ! Restore my geometry
>>
>>      call geom_reset(1)                    ! Force regen. of Jacobians etc.
>>
>>      return
>>      end
>> c-----------------------------------------------------------------------
>>
>>
>> Paul
>>
>>
>>
>>
>