CFD Online Logo CFD Online URL
Home > Forums > ANSYS Meshing & Geometry

[ICEM] Simple periodicity problem

Register Blogs Members List Search Today's Posts Mark Forums Read

LinkBack Thread Tools Display Modes
Old   June 18, 2010, 04:50
Default Simple periodicity problem
New Member
Join Date: Jun 2010
Posts: 3
Rep Power: 9
freekeer is on a distinguished road
Sponsored Links
Hi guys,

I'm new in CFD.

I've been working for a few weeks on a model of combustor, drawing it with UG, and now I'm trying to mesh it with ICEM.
I keep having a problem with the periodical options (I have cut a 60 part to use the symetry of the device), so I decided to cut a small part of my combustor and try to make the periodical thing work on it.
Here is what the small part looks like : inlet, outlet, 2 surfaces for the symetry and a top wall.

After completing the meshing, when checking the mesh, I keep having this message in ICEM :

maximum distance from periodic 5.96046e-008
between vertices 409 and 409; Fixed

everytime I try to check it.
When I try to import the file in Fluent and do a check grid, this is what I get :

Zone 37: average rotation angle (deg) = 6.168 (0.242 to 13.324)
stored zone rotation angle (deg) = 0.991
stored axis , (0.000000e+000, 0.000000e+000, 1.000000e+000)
stored origin, (0.000000e+000, 0.000000e+000, 0.000000e+000)

instead of the 60 I wanted.
The periodic conditions seems not to be respected at all.
I've been trying several things, but still cannot make the periodicity work.
Do you guys have an idea where the problem come from ?

I sent the .tin and .uns files of my project here :
Hope it will be enough to make someone able to check what is going wrong...
freekeer is offline   Reply With Quote
Sponsored Links

Old   June 19, 2010, 09:42
Default Mesh is fine.
Retired from CFD Online
PSYMN's Avatar
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,665
Blog Entries: 1
Rep Power: 39
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
I think you just have a significant digits problem...

Your axis endpoints have a lot of trailing digits and exceed the precision of the mesher. The mesher then finds the problem and fixes it (notes you were 5.9 e-8 off periodic)... This is not a significant distance off (6 orders of magnitude smaller than your mesh size.) Perhaps if you centered your geometry on 0 0 0 or at least on a number where you had a more absolute number... But I don't think precision is stopping you.

I am guessing you didn't setup your bocos correctly?

Or perhaps the problem is that your one periodic surface just has surface, while the other has curves, points and surface (shells, lines and nodes). I am not sure how sensitive Fluent is to this.

Check with the Fluent Forum for tips about setting up periodic problems...
PSYMN is offline   Reply With Quote

Old   August 8, 2016, 09:38
New Member
Join Date: Aug 2016
Posts: 1
Rep Power: 0
mstan is on a distinguished road
I have the same problem. I have tried evrything and it does not work
mstan is offline   Reply With Quote


icem periodicity

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Simple heat conduction problem masb OpenFOAM 10 November 17, 2016 10:53
Problem with a simple UDF to calculate cell-averaged particle values kmayank FLUENT 1 January 18, 2011 02:40
Fluent periodicity problem CFD_boy FLUENT 0 January 14, 2006 13:47
Simple Divergence Problem Cb Siemens 1 February 17, 2005 11:46
? Simple CFD problem Davy Main CFD Forum 0 August 21, 1998 06:19

Sponsored Links

All times are GMT -4. The time now is 20:32.