[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 08:14:05 CST 2012
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
>>
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>>
>
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--
Jean-Christophe
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