## Problems with periodicity by rotation

Questions and remarks about code_saturne usage
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quarian_engineer
Posts: 24
Joined: Wed Jul 01, 2015 8:35 am

### Problems with periodicity by rotation

Hello dear all,

I have some problems with definition of periodic boundaries by rotation. It doesn't work even with very simple geometry: http://mars.workupload.com/image/SjI62A3u (2 grey planes are supposed to be periodic).

At first try I have set periodicity by rotation like this:
periodic boundaries: plane_1, plane_2
angle: 90 deg
axis: 1,0,0
inv. point: 0,0,0

Than, separated:
periodic boundaries: plane_1
angle: 270 deg
axis: 1,0,0
inv. point: 0,0,0

periodic boundaries: plane_2
angle: 90 deg
axis: 1,0,0
inv. point: 0,0,0

-------
But it didn't work again. Every time the same error: some BC's are incomplete or incorrect. Other boundaries (inlet, outlet, wall) are defined correctly.

What am I doing wrong?

Brian Angel

### Re: Problems with periodicity by rotation

Hello,

You only need to specify one periodic boundary set. Can you try the following under the entry "Selection Criteria" on the "Periodic Boundaries" panel:

plane_1 or plane_2

That should work.

Regards,

Brian Angel.
quarian_engineer
Posts: 24
Joined: Wed Jul 01, 2015 8:35 am

### Re: Problems with periodicity by rotation

Hello Brian and thanks for your answer. Unfortunately it doesn't work too. How do you mean I should define the other plane(2), if only plane_1 was set to periodic? I thought about "free inlet/outet" with head loss coef. K = 0; but it gave me the same error about incomplete or false bc's.

It works only if I define plane_1 and plane_2 as walls, but they should be periodic. =/

Could you help me again?
Thanks
Last edited by quarian_engineer on Wed Jul 15, 2015 8:44 am, edited 1 time in total.
quarian_engineer
Posts: 24
Joined: Wed Jul 01, 2015 8:35 am

### Re: Problems with periodicity by rotation

Periodicity by translation between Inlet/Outlet works also perfectly, if I set Plane_1 and Plane_2 as walls.

Maybe I define the axis of rotation incorrectly? (1,0,0) ? Or invariation point (0,0,0) ?
Brian Angel

### Re: Problems with periodicity by rotation

Hello,

The attached test case PERIODIC.tgz will show you what I mean. If you look in the Periodic Boundaries panel you will see that the text for coupling the two periodic boundaries that I have called P1 and P2 is "P1 or P2". Hence, you should use the text "plane_1 or plane_2" for your case. When you launch the check mesh you will see in the check_mesh.log file the coupling of these periodic boundaries, please see the attached check_mesh.log file for the test case attached (look for the text "joining number 1").

Also, make sure that the angle of rotation that you have specified is in the correct sense, i.e. a +ve or -ve angle.

Regards,

Brian Angel.
Attachments
check_mesh.log
PERIODIC.tgz
quarian_engineer
Posts: 24
Joined: Wed Jul 01, 2015 8:35 am

### Re: Problems with periodicity by rotation

Weird... I got the same error if I start your case:

"First face with boundary condition definition error (out of 67)
has boundary condition type 0, center (0.0510687, 0.0510687, 0.882903)" (yours)

"First face with boundary condition definition error (out of 2364)
has boundary condition type 0, center (0.980424, 0.0542555, -0.054256)" (mine)

What does it mean?

And how did you get check_mesh.log file?
Brian Angel

### Re: Problems with periodicity by rotation

Hello,

That is strange as the case I uploaded works here without any problems. Can you let me know:

1) how you have generated your Code_Saturne "study" and "case" directories
2) in which directory the volume mesh is located
3) the identity and paths that are shown in the GUI

Can you also upload the volume mesh (if it isn't to large) and the xml file that you are using?

Regards,

Brian Angel.
quarian_engineer
Posts: 24
Joined: Wed Jul 01, 2015 8:35 am

### Re: Problems with periodicity by rotation

Hello again,

so, firstly I use code_saturne 4.0
1) to generate case and study I used command code_saturne create –s ... –c ...
2) Mesh is located in the MESH directory

Hm, I noticed that my .xml file actually doesn't have the .xml-extention. Maybe it could be a problem.
Anyway, I have uploaded the mesh and the xml.

Thanks again!
Brian Angel

### Re: Problems with periodicity by rotation

Hello,

I can't see your xml file and mesh attached to the message. Can you upload them pls?

Regards,

Brian Angel.
quarian_engineer
Posts: 24
Joined: Wed Jul 01, 2015 8:35 am

### Re: Problems with periodicity by rotation

For some reason I can't attach files to the message. Can you download them from hier?

https://www.dropbox.com/sh/b4jrxzqgxjcz ... uAKMa?dl=0