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

[Technical] Unspecified boundary types in the grids created employing Pointwise

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

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   February 2, 2010, 05:30
Default Unspecified boundary types in the grids created employing Pointwise
  #1
New Member
 
Arash Eslamdoost
Join Date: Mar 2009
Location: Gothenburg, Sweden
Posts: 5
Rep Power: 17
arash is on a distinguished road
When using the revolve or extrude mesh in Pointwise, often some internal faces are created in the internal field which at the end remain as unspecified boundary types. These types of boundaries are problematic in OpenFOAM. Removing these unspecified boundaries results in removing the blocks sharing any of these certain boundaries (patches).

According to this, would you please let me know whether any of you have had similar problem or not? If so, how did you manage to fix that?

BTW, its is possible to remove such unused patches in GAMBIT without causing any other changes in the created grid; but, how should fix this just using Pointwise?

Regards,
Arash
arash is offline   Reply With Quote

Old   February 2, 2010, 18:09
Post Try Grid, Merge... Before Extruding
  #2
Senior Member
 
rmatus's Avatar
 
Rick Matus
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 116
Rep Power: 17
rmatus is on a distinguished road
If you have unspecified internal faces in an extruded block, it most likely means the domains you started the extrusion from had some gaps between them. (Unmerged connectors in Pointwise-speak.)

You can easily check this by going to the Grid, Merge... panel. If there are gaps they will be outlined in red, and you can use the tools in Grid, Merge... to heal them.

Once they are merged, you can do the extrusion and there should be no unspecified internal faces.
rmatus is offline   Reply With Quote

Old   February 2, 2010, 20:16
Default
  #3
New Member
 
Arash Eslamdoost
Join Date: Mar 2009
Location: Gothenburg, Sweden
Posts: 5
Rep Power: 17
arash is on a distinguished road
Hi Rick,
Of-course, that could be a reason but the case I'm talking about is rather different. To be more clear, just imagine a meshed rectangle. If you rotate this rectangle about one of its axis 360 degrees to create a cylinder, you'll find that finally there is a face inside the field which is exactly located on the axis of rotation (I don't know if it is right to call that a face!). This is the unspecified boundary type which I mean. If you remove that face the entire block would be disappeared.
arash is offline   Reply With Quote

Old   February 3, 2010, 09:31
Default Try setting a cyclic boundary condition
  #4
Senior Member
 
rmatus's Avatar
 
Rick Matus
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 116
Rep Power: 17
rmatus is on a distinguished road
Sorry, I was imagining the problem incorrectly. There is some discussion in this thread about the boundary conditions to use on a pole (singularity) as you have in this axisymmetric case. It looks like you should use a cyclic bc on the pole face.

To do that in Pointwise, go to the CAE, Set Boundary Conditions... panel. Click on New and then double click in the Name field of the new entry in the Boundary Conditions table to type whatever name you want to give that BC. Double click in the Type field and when the pull-down activates choose Cyclic for the BC type. Finally, select the face you want to apply this BC to from the display window and then click on the box in the Set column of the table to apply this BC to that face (or faces if you picked more than one).

Hope this helps.

Quote:
Originally Posted by arash View Post
Hi Rick,
Of-course, that could be a reason but the case I'm talking about is rather different. To be more clear, just imagine a meshed rectangle. If you rotate this rectangle about one of its axis 360 degrees to create a cylinder, you'll find that finally there is a face inside the field which is exactly located on the axis of rotation (I don't know if it is right to call that a face!). This is the unspecified boundary type which I mean. If you remove that face the entire block would be disappeared.
rmatus is offline   Reply With Quote

Old   February 9, 2010, 09:35
Default
  #5
New Member
 
Arash Eslamdoost
Join Date: Mar 2009
Location: Gothenburg, Sweden
Posts: 5
Rep Power: 17
arash is on a distinguished road
Rick, thanks for your instructions; now it's working.
arash is offline   Reply With Quote

Old   February 9, 2010, 09:56
Default
  #6
Senior Member
 
rmatus's Avatar
 
Rick Matus
Join Date: Mar 2009
Location: Fort Worth, Texas, USA
Posts: 116
Rep Power: 17
rmatus is on a distinguished road
Arash, happy to hear that worked.
rmatus is offline   Reply With Quote

Reply

Tags
gambit, grid, openfoam, pointwise, unspecified boundary type

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
hybrid mesh created by pointwise fails mesh check in fluent due to left-handed faces Hamid.de Pointwise & Gridgen 4 November 9, 2016 11:20
Question about heat transfer coefficient setting for CFX Anna Tian CFX 1 June 16, 2013 06:28
Low Mixing time Problem Mavier CFX 5 April 29, 2013 00:00
boundary types don't appear in boundary condition menu stimpy FLUENT 0 December 15, 2010 03:33
Regarding FoamX running Kindly help out hariya03 OpenFOAM Pre-Processing 0 April 18, 2008 04:26


All times are GMT -4. The time now is 18:06.