CFD Online Discussion Forums - periodic shadow faces

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periodic shadow faces

Hello,

I will be grateful if someone could explain me how to deal with periodic grids in FLUENT. I have created periodic grid in GAMBIT, where everything was going without problems, but mesh check failes in FLUENT. Could someone advice me what is the problem. I was asking people on GAMBIT sub-forum

http://www.cfd-online.com/Forums/ans...riodic-bc.html

but it seems that they cannot help.

The fluent mesh check shows non-existant (x,y)-periodic translations:

Mesh Check

Domain Extents:
x-coordinate: min (m) = 0.000000e+000, max (m) = 1.000000e+000
y-coordinate: min (m) = 0.000000e+000, max (m) = 1.000000e+000
z-coordinate: min (m) = 0.000000e+000, max (m) = 1.000000e+000
Volume statistics:
minimum volume (m3): 3.333333e-004
maximum volume (m3): 5.684532e-003
total volume (m3): 1.000000e+000
Face area statistics:
minimum face area (m2): 1.000000e-003
maximum face area (m2): 6.757963e-002
Checking number of nodes per cell.
Checking number of faces per cell.
Checking thread pointers.
Checking number of cells per face.
Checking face cells.
Checking cell connectivity.
Checking bridge faces.
Checking right-handed cells.
Checking face handedness.
Checking face node order.
Checking closed cells.
Checking contact points.
Checking element type consistency.
Checking boundary types:
Checking face pairs.
Checking wall distance.
Checking node count.
Checking nosolve cell count.
Checking nosolve face count.
Checking face children.
Checking cell children.
Checking storage.
Checking periodic boundaries.
Periodic zone 3: x-translation: min (m) = -1.284619e-001, max (m) = 2.012138e-001
y-translation: min (m) = -1.674896e-001, max (m) = 1.632244e-001
z-translation: min (m) = 1.000000e+000, max (m) = 1.000000e+000
Done.

WARNING: Mesh check failed.

Thanks in advance

Truffaldino

There should be no problem in Fluent if periodicity is correctly defined in Gambit. I wonder if you connected the faces periodically in Gambit i.e., if you select/mesh one face, the other one should get selected/meshed automatically. Also, the order (arrow direction) of edge selection when connecting the periodic faces should be the same for both the faces. If you took care of these things already, then I am not sure if this is some other problem. As you mentioned, the extents for X and Y seem strange.

Thanks guys, Thanks a lot mAx,

The problem is fixed and eliminated shadow faces are reordered with the help of the manual given by mAx in the link: http://my.fit.edu/itresources/manual...ug/node180.htm

Fluent command

grid http://my.fit.edu/itresources/manual.../ug/img463.gif modify-zones http://my.fit.edu/itresources/manual.../ug/img464.gif repair-periodic

eliminates unexistent translations! :

/mesh/modify-zones> repair-periodic
Periodic zone [()] periodic
Repair translational periodic zone? [yes] y

computed translation deltas: 0.000000 0.000000 1.000000
reordered 163 periodic shadow faces

I am still wandering what was wrong with GAMBIT?

Thanks again
Truffaldino

I can't acces to the links attached.

Hello everybody,

I'm having a similar problem when linking face meshes and I'm trying to acces to mAx's links but it says that I'm not allowed to acces the server. Can anyone refresh the links or upload the documents please.

Regards.

Thank you very much mAx.
I was having problems with linking the periodic mesh faces, but I figured out that I had to uncheck the option of reverse orientation and select the correct vertex. :)

Regards,
Luis Carlos Roa

Change in repair-periodic location

This solution worked for me.

There was a change in the location of repair-periodic, it can now be found in:

/mesh/repair-improve/repair-periodic