CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > ANSYS Meshing & Geometry

[ICEM] Trouble with an unstructured, rotational periodic mesh

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

Like Tree1Likes
  • 1 Post By timotie87

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 25, 2020, 20:24
Default Trouble with an unstructured, rotational periodic mesh
  #1
New Member
 
Tim
Join Date: May 2016
Posts: 11
Rep Power: 6
timotie87 is on a distinguished road
I am trying to set up a rotational periodic mesh in ICEM. I have a simple half cylinder domain, and would like to set up the mesh so that faces A1 and A2 are conforming, similar with B1 and B2. I have done these steps:

1. Global Mesh Setup > Set up Periodicity
2. Rotational Periodic
3. Base: 0 0 0, Axis 0 0 1, Sectors 2 (for 180 degree)

I am making a unstructured mesh, using the Quick (Delaunay), but the resulting mesh does not produce conforming meshes on these surfaces. Any suggestions?
Attached Images
File Type: png rota.png (123.8 KB, 22 views)
syavash likes this.
timotie87 is offline   Reply With Quote

Old   July 11, 2020, 05:07
Default
  #2
Senior Member
 
Ehsan Asgari
Join Date: Apr 2010
Posts: 445
Rep Power: 14
syavash is on a distinguished road
Quote:
Originally Posted by timotie87 View Post
I am trying to set up a rotational periodic mesh in ICEM. I have a simple half cylinder domain, and would like to set up the mesh so that faces A1 and A2 are conforming, similar with B1 and B2. I have done these steps:

1. Global Mesh Setup > Set up Periodicity
2. Rotational Periodic
3. Base: 0 0 0, Axis 0 0 1, Sectors 2 (for 180 degree)

I am making a unstructured mesh, using the Quick (Delaunay), but the resulting mesh does not produce conforming meshes on these surfaces. Any suggestions?
Hi Tim,

I have also faced the exactly same issue! I produce mesh using Delauny method with rotational periodic boundaries, but when I check in Fluent, it tells me that the surface mesh does not match between two!

Did you manage to find a solution?

Kind regards,
syavash
syavash is offline   Reply With Quote

Old   July 17, 2020, 15:32
Default
  #3
New Member
 
Tim
Join Date: May 2016
Posts: 11
Rep Power: 6
timotie87 is on a distinguished road
Quote:
Originally Posted by syavash View Post
Hi Tim,

I have also faced the exactly same issue! I produce mesh using Delauny method with rotational periodic boundaries, but when I check in Fluent, it tells me that the surface mesh does not match between two!

Did you manage to find a solution?

Kind regards,
syavash
Hello Syavash,

Yes, I was able to solve my problem somewhat. The Delauny method is not able to produce a rotational symmetric mesh by itself. My workaround was to use the Robust Octree method to create the volume mesh and accompanying surface mesh. I then smoothed the mesh to a quality I was happy with, and then deleted all of the volume elements. This left me with a rotational periodic surface mesh of my domain with no volume mesh. I then remade the volume mesh with the Delauny method, making sure to select "Existing Mesh" in the input. This will use the periodic surface mesh and make a nice Delauny volume mesh to go with it. Make sure to check the periodicity before and after the volume meshing. Hope this works for you like it did for me... let me know!

Cheers,
Tim
timotie87 is offline   Reply With Quote

Old   July 18, 2020, 09:08
Default
  #4
Senior Member
 
Ehsan Asgari
Join Date: Apr 2010
Posts: 445
Rep Power: 14
syavash is on a distinguished road
Quote:
Originally Posted by timotie87 View Post
Hello Syavash,

Yes, I was able to solve my problem somewhat. The Delauny method is not able to produce a rotational symmetric mesh by itself. My workaround was to use the Robust Octree method to create the volume mesh and accompanying surface mesh. I then smoothed the mesh to a quality I was happy with, and then deleted all of the volume elements. This left me with a rotational periodic surface mesh of my domain with no volume mesh. I then remade the volume mesh with the Delauny method, making sure to select "Existing Mesh" in the input. This will use the periodic surface mesh and make a nice Delauny volume mesh to go with it. Make sure to check the periodicity before and after the volume meshing. Hope this works for you like it did for me... let me know!

Cheers,
Tim
Hi Tim,

Thanks for your thorough explanation. I think I figured out how to do it. Only one point I have doubt about.
I have defined the periodicity in the Global mesh parameters. However, when I check the periodicity by doing right-click on the mesh tree, nothing is added to the screen!
Further, I guess smoothing the surface mesh is also possible without the volume mesh (delete the latter first)?
I appreciate your valuable help.

Regards
syavash
syavash is offline   Reply With Quote

Old   July 22, 2020, 12:28
Default
  #5
New Member
 
Tim
Join Date: May 2016
Posts: 11
Rep Power: 6
timotie87 is on a distinguished road
Yes, delete the volume mesh elements first, and the smooth the remaining surface mesh.
timotie87 is offline   Reply With Quote

Reply

Tags
icem 18.1, mesh 3d, periodic, unstructured

Thread Tools Search this Thread
Search this Thread:

Advanced Search
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 Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
how to set periodic boundary conditions Ganesh FLUENT 14 November 26, 2018 11:26
sliding mesh problem in CFX Saima CFX 45 September 22, 2015 10:53
[snappyHexMesh] snappyHexMesh won't work - zeros everywhere! sc298 OpenFOAM Meshing & Mesh Conversion 2 March 27, 2011 21:11
Icemcfd 11: Loss of mesh from surface mesh option? Joe CFX 2 March 26, 2007 18:10
unstructured vs. structured grids Frank Muldoon Main CFD Forum 1 January 5, 1999 10:09


All times are GMT -4. The time now is 10:32.