Hi Jon,


It's been awhile since I've run the cyclic BCs that you're trying to use.

(Here:  cyclic = periodic + turning through an angle.)


I can't recall the full workflow at the moment (and am not in a position

to check), but I think you'll have better luck if you build a straight mesh,

run genmap, and then morph the geometry into the desired curved

shape in usrdat2().


The reason for doing so is that you'll then be guaranteed to have

the correct mesh connectivity.


hth,


Paul


From: Nek5000-users <nek5000-users-bounces@lists.mcs.anl.gov> on behalf of nek5000-users@lists.mcs.anl.gov <nek5000-users@lists.mcs.anl.gov>
Sent: Saturday, January 13, 2018 1:00:48 PM
To: nek5000-users@lists.mcs.anl.gov
Subject: Re: [Nek5000-users] Periodicity with curvature
 
My apologies, can you clarify what you mean?
I made global refinements one more time, and re-assigned the periodic BCs within prex. For this 2D case (attached), I have linked the 8 element sides with the right 8 sides. All other sides are walls.

Thank you,
Jon

On Sat, Jan 13, 2018 at 12:49 PM, <nek5000-users@lists.mcs.anl.gov> wrote:
can you try again with at least 3 elements in other direction.
Thanks for the quick response. I made some global refinements but it seems I'm still getting the same error with genmap.

Attached is the new .rea file with 4 elements in the periodic direction.


On Sat, Jan 13, 2018 at 12:32 PM, <nek5000-users@lists.mcs.anl.gov> wrote:
You need to have at least three elements in the periodic direction. 
Dear Nek Users,

I am trying to get periodicity to work in the lastest version of Nek. I've made an extremely simple mesh within prenek (prex) in polar coordinates and cannot seem to run this case. When I run genmap, I get the error below. Did I do something wrong in setting up this mesh?



>> genmap
 reading a.rea
Input mesh tolerance (default 0.2):
NOTE: smaller is better, but generous is more forgiving for bad meshes.
0.01
 reading mesh data ...
 start locglob_lexico:           4           2           8   1.0000000000000000E-002
 locglob:           1           1           8
 locglob:           2           5           8
 locglob:           1           6           8
 locglob:           2           6           8
 done locglob_lexico:           6           6           8           2
 start periodic vtx:           2           6
     1     4     4  Matrix:    x0
  1   x0    1.0000E+00  1.0000E+00  5.4347-323  4.9407-324
  2   x0   -3.5355E-01  3.5355E-01  6.9423-310  6.9423-310
  3   x0    3.5355E-01 -3.5355E-01  6.9529-310  6.9529-310
  4   x0    6.9423-310  6.9529-310  2.3477-313  3.1632-317
     2     4     4  Matrix:    x1
  1   x1    1.0000E+00  1.0000E+00  6.3240-322  0.0000E+00
  2   x1   -3.5355E-01  3.5355E-01  0.0000E+00  6.9423-310
  3   x1   -3.5355E-01  3.5355E-01  6.9423-310  6.9529-310
  4   x1    6.9423-310  6.9423-310  6.9423-310  6.9529-310
     1     4     4  Matrix:    z0
  1   z0    1.0000E+00  1.0000E+00  5.4347-323  4.9407-324
  2   z0   -2.1213E+00 -1.4142E+00  6.9423-310  6.9423-310
  3   z0    2.1213E+00  1.4142E+00  6.9529-310  6.9529-310
  4   z0    6.9423-310  6.9529-310  2.3477-313  3.1632-317
     2     4     4  Matrix:    z1
  1   z1    1.0000E+00  1.0000E+00  6.3240-322  0.0000E+00
  2   z1    1.4142E+00  2.1213E+00  0.0000E+00  6.9423-310
  3   z1    1.4142E+00  2.1213E+00  6.9423-310  6.9529-310
  4   z1    6.9423-310  6.9423-310  6.9423-310  6.9529-310
           1 3  0  1.00000000E-03  2.12132000E+00 abort: FACE MATCH FAIL
           2 4  3  2.12132000E-03  1.00000031E+00 abort: FACE MATCH FAIL

           0  quit





The mesh within my .rea file is as follows:
   20.0000       20.0000      -8.00000      -4.00000     XFAC,YFAC,XZERO,YZERO
 **MESH DATA** 1st line is X of corner 1,2,3,4. 2nd line is Y.
         2         2         2 NEL,NDIM,NELV
      ELEMENT          1 [    1A]    GROUP     0
  -2.121320      -1.414213     -0.8742276E-07 -0.1311341E-06
   2.121320       1.414213       2.000000       3.000000
      ELEMENT          2 [    1B]    GROUP     0
 -0.1311341E-06 -0.8742276E-07   1.414213       2.121320
   3.000000       2.000000       1.414213       2.121320
  ***** CURVED SIDE DATA *****
         4 Curved sides follow IEDGE,IEL,CURVE(I),I=1,5, CCURVE
  2  1  -2.00000       0.00000       0.00000       0.00000       0.00000     C
  4  1   3.00000       0.00000       0.00000       0.00000       0.00000     C
  2  2  -2.00000       0.00000       0.00000       0.00000       0.00000     C
  4  2   3.00000       0.00000       0.00000       0.00000       0.00000     C
  ***** BOUNDARY CONDITIONS *****
  ***** FLUID   BOUNDARY CONDITIONS *****
 P    1  1   2.00000       3.00000       0.00000       0.00000       0.00000
 W    1  2   0.00000       0.00000       0.00000       0.00000       0.00000
 E    1  3   2.00000       1.00000       0.00000       0.00000       0.00000
 W    1  4   0.00000       0.00000       0.00000       0.00000       0.00000
 E    2  1   1.00000       3.00000       0.00000       0.00000       0.00000
 W    2  2   0.00000       0.00000       0.00000       0.00000       0.00000
 P    2  3   1.00000       1.00000       0.00000       0.00000       0.00000
 W    2  4   0.00000       0.00000       0.00000       0.00000       0.00000
  ***** NO THERMAL BOUNDARY CONDITIONS *****

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