Periodic BC and Unstructured Mesh

Jenny_W · May 20, 2013, 12:00

Hi Everyone,
I have a problem creating periodic boundary conditions. If you know the solutions, please help.

I created a geometry in ICEM CFD and tried to create the rotational periodic boundary condition in FLUENT by typing at the interface
define>boundary-conditions>modify-zones>make-periodic

However, FLUENT shows
Warning: differing number of faces on these threads.
zone 36: matched 0 out of 4112 faces.
zone 35: matched 0 out of 4237 faces.
Error: Failed to make zones periodic.
Error Objects: #f

Can FLUENT create periodic boundary condition on unstructured mesh? It seems to fail because the number of faces on the periodic zone does not match that of the shadow zone.
Thank you in advance,
Jenny

Jenny_W · May 23, 2013, 16:25

Hi,
Does anyone know if FLUENT can create periodic boundary condition on unstructured mesh?
It always shows:
Error: Failed to make zones periodic.
Thanks,
Jenny

Jabba · May 23, 2013, 19:16

Fluent can create periodic boundaries on unstructured meshes but the faces mesh must be conformal

I believe that the user guide lists to steps to make the meshes equal
you can also do it with your mesher

regards

Quote:

Originally Posted by Jenny_W

Hi,
Does anyone know if FLUENT can create periodic boundary condition on unstructured mesh?
It always shows:
Error: Failed to make zones periodic.
Thanks,
Jenny

Jenny_W · May 26, 2013, 07:35

Hi Jabba,
Thank you for your recommendations.
After reading your comment, I followed non-conformal mesh periodic boundary condition steps (rotational) in FLUENT user guide (change boundary condition to interface then create periodic condition in mesh interfaces).
However, FLUENT reported the error "couldn't intersect thread 35 and 36".
I have checked the offset angle so I don't know what I did wrong.
Do you have any suggestions?
Thank you,
Jenny

Jabba · May 27, 2013, 11:08

Hello Jenny

I'm not sure about what this error means
I would recommend that you make the meshes of the faces you want to make periodic equal using a mesh generator, not fluent
this was what I have done

with ansys meshing, this is pretty straightforward.. icemcfd should have this capability too
then you import the mesh in fluent and just make them periodic through TUI as you tried before

regards

May 20, 2013, 12:00	Periodic BC and Unstructured Mesh	#1
Jenny_W Member Jenny Join Date: Apr 2011 Posts: 34 Rep Power: 15	Hi Everyone, I have a problem creating periodic boundary conditions. If you know the solutions, please help. I created a geometry in ICEM CFD and tried to create the rotational periodic boundary condition in FLUENT by typing at the interface define>boundary-conditions>modify-zones>make-periodic However, FLUENT shows Warning: differing number of faces on these threads. zone 36: matched 0 out of 4112 faces. zone 35: matched 0 out of 4237 faces. Error: Failed to make zones periodic. Error Objects: #f Can FLUENT create periodic boundary condition on unstructured mesh? It seems to fail because the number of faces on the periodic zone does not match that of the shadow zone. Thank you in advance, Jenny

May 23, 2013, 16:25		#2
Jenny_W Member Jenny Join Date: Apr 2011 Posts: 34 Rep Power: 15	Hi, Does anyone know if FLUENT can create periodic boundary condition on unstructured mesh? It always shows: Error: Failed to make zones periodic. Thanks, Jenny

May 26, 2013, 07:35		#4
Jenny_W Member Jenny Join Date: Apr 2011 Posts: 34 Rep Power: 15	Hi Jabba, Thank you for your recommendations. After reading your comment, I followed non-conformal mesh periodic boundary condition steps (rotational) in FLUENT user guide (change boundary condition to interface then create periodic condition in mesh interfaces). However, FLUENT reported the error "couldn't intersect thread 35 and 36". I have checked the offset angle so I don't know what I did wrong. Do you have any suggestions? Thank you, Jenny

May 27, 2013, 11:08		#5
Jabba New Member Join Date: Nov 2011 Posts: 27 Rep Power: 15	Hello Jenny I'm not sure about what this error means I would recommend that you make the meshes of the faces you want to make periodic equal using a mesh generator, not fluent this was what I have done with ansys meshing, this is pretty straightforward.. icemcfd should have this capability too then you import the mesh in fluent and just make them periodic through TUI as you tried before regards