[Convoy]

Hello everyone, I am working on a project in which I have to model a flow pattern through a 1-D Rhombohedral unit cell(picture attached).
In the fig.,fluid enters the unit cell from the lower face and flows in the +y direction. I need to make the 2 opposite faces periodic(marked as yellow faces).
I have tried to do this by typing the following command in the TUI of Fluent:
mesh-->modify-zones-->mp
Periodic zone [()] 7
Shadow zone [()] 9
Rotational periodicity? (if no, translational) [yes] n
Create periodic zones? [yes] y
Auto detect translational vector? [yes] y

computed translation deltas: -0.028085 -0.000148 -0.000000
zone 7: matched 0 out of 478 faces.
zone 9: matched 0 out of 478 faces.

Error: Failed to make zones periodic.
Error Object: #f

What do I do?
Is there a way I can make meshing in the 2 faces identical in Workbench Meshing itself?

Any help will be much appreciated.

Thanks in advance..

[philus]

are you on serial or parallel mode? I'm not shure but try to open fluent in serial mode when you want to set periodic conditions..

[Convoy]

Thanks for your reply.. I am not sure about the mode whether serial or parallel. Where can we know that?

[philus]

normally the window title should be "<case name> parallel_if_parallel Fluent@<computer name> [<parameters>]"
otherwise relaunch Fluent and check the voice "processing optinos" on the launcher

[Convoy]

Btw, just found that the mode is serial (written in Fluent Launcher)

[philus]

ok, it is not the source of the problem sorry but my help can't go further

good luck!

[Convoy]

@philus, no problem mate

[Tharanga]

Hey,
Are you able to do this in fluent? I'm having the same problem.

Regards
Tharanga

[Convoy]

@Tharanga, sorry mate...haven't found a solution yet

[maverick123]

@ Convoy

Have you tried non-conformal periodic interfaces? For that you need to change the zone-type of these 2 face zones to interface.

[Convoy]

@maverick123, yeah I did try making the two surfaces as interfaces and applying non-conformal periodic boundary condition. But on doing that, when I tried to make the two interfaces periodic by going to the "Mesh Interface" window, I didn't know what Offset value I should take. When I assumed the Offset as (0,0,0) I got the error message "Couldn't intersect threads 7 and 9". 7 and 9 are the zone IDs.

[maverick123]

@Convoy
You are using wrong offset. It can never be (0,0,0). If the two faces are in the same direction as one of your axis then offset will be (X,0,0) where X is the distance between them.

[FJSJ]

Hi guys,

I don't know exactly if you are looking for something like this video:

Make periodic bc in Fluent

[renatovj]

I have a question for you guys...

Do the boundaries need to have an angle with respeect to the x-axis to set the periodic boundaries?

I am trying to set the two horizontal boundaries in the picture attached as periodic...

[Tharanga]

Hi,
If you want to make it transitional, answer is no. I managed to give transitional condition using the consol. Previously, I tried with unstructured mesh it didnot work. When the mesh changed to structured mesh, it did work. Cheers.

[Jufri]

http://www.cfd-online.com/Forums/flu...-tutorial.html

Has a way to make a cyclic symmetry. Maybe it could be applied to your geometry