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

O-grid generation on segmented confuser

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

Reply
 
LinkBack Thread Tools Display Modes
Old   July 22, 2010, 06:35
Default O-grid generation on segmented confuser
  #1
New Member
 
Daniel Laki
Join Date: Jul 2010
Posts: 5
Rep Power: 7
LD696 is on a distinguished road
Hi!

I have to simulate a confuser with 19 "subchannels". Since this is my first 3D simulation on such a (at least for me) complex geometry, I got stuck with the blocking. I got a suggestion, that I should create an O-grid in the central channel and then "expand" it to the outer segments. Is that possible somehow? Any goood idea about the blocking strategy is appreciated. I'm using ICEM CFD.

Thanks for the replies.

Daniel
Attached Images
File Type: jpg segmented.jpg (38.6 KB, 34 views)
File Type: jpg segmented_f.jpg (36.6 KB, 27 views)
LD696 is offline   Reply With Quote

Old   July 23, 2010, 09:47
Default
  #2
Senior Member
 
PSYMN's Avatar
 
Simon Pereira
Join Date: Mar 2009
Location: Ann Arbor, MI
Posts: 2,662
Blog Entries: 1
Rep Power: 35
PSYMN has a spectacular aura aboutPSYMN has a spectacular aura about
Yup, it is a simple topology, perfect for Ogrids... Is it just structural or is there a fluid flowing thru? I will assume the later and assume that there are surfaces across both ends (inlet and outlet) to close them off.

Start with a single box around this model. Put an Ogrid in that box with faces at the ends. This will give you your initial Ogrid of 5 blocks.

Reduce the index control so you have a single plane (5 faces) on the small end of the pipe. Associate the outer 4 edges with he circle and move them into place... Move the center 4 verts inside the middle circle.

Reset the index control and then use the Align verts command to align the other side.

Then associate the outer edges on the other side to the larger end of the pipe...

After that it is mostly about splitting. Split the Ogrid to get each of the radial steps... Split a vertical and horizontal edge to get the radial structures. Split along the cone if there are any internal walls I can't see in this pic. Between splits, Associate edges that align with curves. You may also want to associate verts with points since this model will have a lot of baffle corners (it just keeps it tidier).

The only tricky thing for this model is that you are dealing with zero thickness baffles. Since the blocking material on both sides is the same, the default is not to create shells on these faces. To force shells, you will need to use the Associate faces option. Either choose closest surface or select the specific parts.

When you are done, please post a final pic... ;^)
PSYMN is offline   Reply With Quote

Old   July 23, 2010, 15:25
Default
  #3
New Member
 
Daniel Laki
Join Date: Jul 2010
Posts: 5
Rep Power: 7
LD696 is on a distinguished road
Thanks for the help I'll post a pic as soon as I can.
LD696 is offline   Reply With Quote

Old   August 16, 2010, 07:42
Default
  #4
New Member
 
Daniel Laki
Join Date: Jul 2010
Posts: 5
Rep Power: 7
LD696 is on a distinguished road
Thanks to your help I managed to finish the blocking...I think.

Unfortunately due to the high number of cells (~ 4 million), the lack of time and computational capacity available, I'll have to abandon the project for a while now, so I can't really test the resulting mesh.

Anyway, thank you for the help; I included pictures of the complete block structure and five cross sections.
Attached Images
File Type: jpg 1.jpg (70.5 KB, 20 views)
File Type: jpg complete.jpg (95.1 KB, 23 views)
LD696 is offline   Reply With Quote

Reply

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
need help for generation grid aya FLUENT 11 March 4, 2008 15:46
Combustion Convergence problems Art Stretton Phoenics 5 April 2, 2002 05:59
Latest News in Mesh Generation Robert Schneiders Main CFD Forum 1 February 18, 2000 01:48
Latest new in mesh generation Robert Schneiders Main CFD Forum 0 February 16, 2000 08:12
Latest news in mesh generation Robert Schneiders Main CFD Forum 0 March 2, 1999 05:07


All times are GMT -4. The time now is 14:21.