[Nek5000-users] Periodic B.C and Genmap Issue

nek5000-users at lists.mcs.anl.gov nek5000-users at lists.mcs.anl.gov
Fri Nov 9 08:15:29 CST 2012


PS: I have tried to send an email to cmeador at tamu.edu first, but I got a
return to sender error.

On 9 November 2012 15:14, <nek5000-users at lists.mcs.anl.gov> wrote:

> Hi Nek's,
>
> This question actually concerns the matlab code to transfer mesh from
> gambit to Nek. So far, I have used it to mesh pipe flow with a given inlet
> and oulet and it worked perfectly fine. I would like now to use periodic
> conditions between the inlet and oulet. As a matter of fact, I have
> remeshed my pipe with gambit and created 2 set of boundary conditions:
>
>    1. the pipe wall
>    2. a set called 'periodic' that contains all the faces from the inlet
>    and outlet
>
> I then export the mesh under the .neu format. The thing is when I use the
> matlab code to produce my pipe.rea file, here is what I get for any faces
> subject to the periodic condition:
>
> P       1  5         0       0.00000       0.00000       0.00000
> 0.00000
>
> The 5th face of element 1 should be connected to another element, but
> nothing comes out the matlab code. Have I missed something while meshing or
> is there any specific thing to do with the matlab code to be able to handle
> such periodic boundary conditions?
>
> Sincerely yours,
>
> JC
> On 24 June 2010 20:29, <nek5000-users at lists.mcs.anl.gov> wrote:
>
>>
>> There should normally be two spaces after each bc in genbox.
>>
>> Regarding format in the .rea file, this is a problem with
>> mixed characters + numbers on the same input line, particularly
>> when the input character string supports blanks.
>>
>> I typically resolve the issue by looking at the source.
>> In this case, connect2.f in the nek/ repo indicates:
>>
>>
>>                IF (NELGT.LT.1000) THEN
>>                   READ(9,50,ERR=500,END=500)
>>      $            CHTEMP,
>>      $            CBC(ISIDE,IEL,IFIELD),ID1,ID2,
>>      $            (BC(II,ISIDE,IEL,IFIELD),II=1,**NBCREA)
>>    50             FORMAT(A1,A3,2I3,5G14.6)
>>                ELSEIF (NELGT.LT.100000) THEN
>>                   READ(9,51,ERR=500,END=500)
>>      $            CHTEMP,
>>      $            CBC(ISIDE,IEL,IFIELD),ID1,ID2,
>>      $            (BC(II,ISIDE,IEL,IFIELD),II=1,**NBCREA)
>>    51             FORMAT(A1,A3,I5,I1,5G14.6)
>>                ELSEIF (NELGT.LT.1000000) THEN
>>                   READ(9,52,ERR=500,END=500)
>>      $            CHTEMP,
>>      $            CBC(ISIDE,IEL,IFIELD),ID1,
>>      $            (BC(II,ISIDE,IEL,IFIELD),II=1,**NBCREA)
>>    52             FORMAT(A1,A3,I6,5G14.6)
>>                ELSE
>>
>>
>> ...
>>
>>
>> Paul
>>
>>
>>
>>
>> On Thu, 24 Jun 2010, nek5000-users at lists.mcs.anl.**gov<nek5000-users at lists.mcs.anl.gov>wrote:
>>
>>  Hi Paul,
>>>
>>> I am having a similar problem.
>>> I am trying to generate a mesh for a 3D periodic channel flow with
>>> periodic
>>> boundary conditions in x and z directions and walls on the y direction.
>>> I use genbox and then genmap. But i got the same error of Shriram.
>>> Note that i am having problems when i am using double periodic BCs :
>>> P  ,P  ,W  ,W  ,P  ,P
>>> but single BCs works fine :
>>> P  ,P  ,W  ,W  ,W  ,W
>>> W  ,W  ,W  ,W  ,P  ,P
>>> W  ,W  ,P  ,P  ,W  ,W
>>>
>>> Do you have a work around or a suggestion?
>>>
>>> Thank you
>>> francesco
>>>
>>>
>>>
>>> My error is
>>>
>>>
>>> reading .rea file data ...
>>> reading .re2 file data ...
>>> start locglob_lexico:           8         512        4096
>>>   0.2000000000000000
>>> locglob:           1           1        4096
>>> locglob:           2           9        4096
>>> locglob:           3          81        4096
>>> locglob:           1         729        4096
>>> locglob:           2         729        4096
>>> locglob:           3         729        4096
>>> locglob:           1         729        4096
>>> locglob:           2         729        4096
>>> locglob:           3         729        4096
>>> done locglob_lexico:       729       729      4096         8
>>> start periodic vtx:         512         729
>>>         1 1  5  3  0.00000000E+00        1 shift
>>>
>>> abort: PERIODIC MISMATCH 2:
>>>        1  5 P    ie
>>>      449  6 P             je
>>>    449.0000000000000       0.0000000000000000E+000 bc
>>>
>>>
>>> My .box file is :
>>>
>>>
>>> turbChannel.rea
>>> 3                       spatial dimension
>>> 1                       number of fields
>>> #
>>> #       comments:       This is the box immediately behind the
>>> #                       refined cylinder in Ugo’s cyl+b.l. run.
>>> #
>>> #
>>> #=============================**===========================
>>> #
>>> Box 1                           Pipe
>>> -8 -8 -8                        Nelx Nely Nelz
>>> 0.0   6.28   1.0                x0 x1   ratio
>>> -1.0   1.0    1.0               y0 y1   ratio
>>> 0.0   3.14   1.0                z0 z1   ratio
>>> P  ,P  ,W  ,W  ,P  ,P           BC’s: (cbx0, cbx1, cby0, cby1, cbz0,
>>> cbz1)
>>>
>>>
>>>
>>>
>>>
>>>
>>>
>>> -----Original Message-----
>>> From: nek5000-users-bounces at lists.**mcs.anl.gov<nek5000-users-bounces at lists.mcs.anl.gov>on behalf of
>>> nek5000-users at lists.mcs.anl.**gov <nek5000-users at lists.mcs.anl.gov>
>>> Sent: Thu 6/24/2010 6:22 PM
>>> To: nek5000-users at lists.mcs.anl.**gov <nek5000-users at lists.mcs.anl.gov>
>>> Subject: [Nek5000-users] Periodic B.C and Genmap Issue
>>>
>>> Hi Paul,
>>>
>>> This post is in reference to the previous post by Michael (dated Jun 22).
>>> When I try to get a map file for a rea file that has periodic vertices, I
>>> get the following error. The rea file was generated the same way as
>>> before
>>> (Gambit -> Nek through Matlab). I checked on Matlab by plotting the
>>> periodic
>>> vertices and confirmed for a few faces that they are indeed periodic.
>>> Also,
>>> as you had earlier suggested (with the new genmap), I tried changing the
>>> tolerances fro 0.09 to 0.2 and I get the same periodic mismatch error.
>>> Could
>>> you provide any leads on where things are going wrong  ? Please find
>>> below
>>> the error message. Thanks.
>>>
>>> <error>
>>> Input (.rea) file name:
>>> domain
>>> Input mesh tolerance (default 0.2):
>>> NOTE: smaller is better, but generous is more forgiving for bad meshes.
>>> 0.09
>>> reading .rea file data ...
>>> start locglob_lexico:           8        3912       31296
>>> 8.99999999999999967E-002
>>> locglob:           1           1       31296
>>> locglob:           2          36       31296
>>> locglob:           3        1224       31296
>>> locglob:           1        4851       31296
>>> locglob:           2        4851       31296
>>> locglob:           3        4851       31296
>>> locglob:           1        4851       31296
>>> locglob:           2        4851       31296
>>> locglob:           3        4851       31296
>>> done locglob_lexico:      4851      4851     31296        10
>>> start periodic vtx:        3912        4851
>>>
>>> abort: PERIODIC MISMATCH 2:
>>>     1093  1 P    ie
>>>        0  1   je
>>>  4.14470000000000029E-003   0.0000000000000000       bc
>>>
>>>
>>>           8  quit
>>>
>>> </error>
>>>
>>>
>>> Regards
>>> Shriram
>>>
>>> ______________________________**_________________
>>> Nek5000-users mailing list
>>> Nek5000-users at lists.mcs.anl.**gov <Nek5000-users at lists.mcs.anl.gov>
>>> https://lists.mcs.anl.gov/**mailman/listinfo/nek5000-users<https://lists.mcs.anl.gov/mailman/listinfo/nek5000-users>
>>>
>>
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>>
>
>
> --
> Jean-Christophe
>
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>


-- 
Jean-Christophe
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