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

problem in prism layer generation

Register Blogs Community New Posts Updated Threads Search

Like Tree2Likes
  • 1 Post By ghorrocks
  • 1 Post By ---joke---

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   June 18, 2008, 14:36
Default problem in prism layer generation
  #1
shrimp
Guest
 
Posts: n/a
Hi guys,

I follow the tutorial of iCEM 11.0 to generate tetra mesh and then want to creat prism layer. But I fail again and agin with errors like these:

face at 118583 173622 230139 has one volume neighbor and no shell element vt1 loc = 15.1891 18.1678 -27.5124 3 elements at face 181849 224649 224804, not all tets PYRA_5 TETRA_4 TETRA_4 PYRA_5 PENTA_6 PENTA_6 PENTA_6 PENTA_6 PYRA_5 TETRA_4 TETRA_4 PYRA_5 TETRA_4 PYRA_5 TETRA_4 PYRA_5 PENTA_6 PENTA_6 PYRA_5 TETRA_4 TETRA_4 some tetrahedra occupy the same volume and that couldn't be fixed .... and 27 more error messages ... orientation errors! writing out prism layer 1 done initializing directions from levelset norm 5805 prism_nodes Assertion failed: has_volume_elements == 0, file compute_marching_dir.C, line 559

This application has requested the Runtime to terminate it in an unusual way. Please contact the application's support team for more information. Application is finished. Error: prism terminated prematurely

Anybody has any idea? Thanks!!
  Reply With Quote

Old   June 19, 2008, 11:51
Default Re: problem in prism layer generation
  #2
myron
Guest
 
Posts: n/a
First make sure your tetra mesh passes all errors and possible problems checks. Sounds like the tet mesh may have some problems.
  Reply With Quote

Old   June 22, 2008, 19:57
Default Re: problem in prism layer generation
  #3
Glenn Horrocks
Guest
 
Posts: n/a
Hi,

These sort of errors usually occur when the mesh is not fine enough to resolve the geometry or the underlying mesh is poor quality. The fix is finer mesh and/or better quality mesh.

Glenn Horrocks
  Reply With Quote

Old   March 26, 2010, 05:21
Default
  #4
New Member
 
Join Date: Mar 2010
Posts: 2
Rep Power: 0
---joke--- is on a distinguished road
Hi

I have had the exact same problem.
Unfortunately, I have not been able to resolve this situation.
My mesh contains 4 Millions tet elements so I suppose it could be fine enough.
But indeed, it works when I ask ICEM to prism only very simple surfaces, so it tends to prove Glenn Horrocks' point.

Please let me know here if any solution has been found except a perfect mesh, which usually never happens in industry

---JOKE---
---joke--- is offline   Reply With Quote

Old   March 26, 2010, 06:03
Default
  #5
Super Moderator
 
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,871
Rep Power: 144
ghorrocks is just really niceghorrocks is just really niceghorrocks is just really niceghorrocks is just really nice
The solution is training and experience. You can earn a good wage as a CFD engineer and the reason is because it is not easy.
Hao Xu likes this.
ghorrocks is offline   Reply With Quote

Old   March 26, 2010, 13:34
Default
  #6
New Member
 
Join Date: Mar 2010
Posts: 2
Rep Power: 0
---joke--- is on a distinguished road
A collegue has found a way to avoid the crash.
This crash happens after extruding the first prism layer because the quality has diminished. Therefore, an easy way to compute prism boundary layer is :
- compute only one layer
- split it (split prism option)

My collegue always used this method so that the prism are more regular and gradients better computed.

Hoping this will help,

---JOKE---
Hao Xu likes this.
---joke--- is offline   Reply With Quote

Reply


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
[snappyHexMesh] SnappyHexMesh - no layer added bejbro OpenFOAM Meshing & Mesh Conversion 5 February 1, 2020 21:05
[ICEM] Fixing tetra Surface Orientations after prism generation siw ANSYS Meshing & Geometry 14 December 1, 2015 16:54
Getting prism to inflate into mixed tet-hex meshes Joe CFX 16 October 10, 2011 08:06
ICEM Prism Layer transition between surface with prism layers and one without TWaung ANSYS Meshing & Geometry 2 October 12, 2009 15:56
problem in solving "wave generation" problem san FLUENT 2 April 4, 2006 00:37


All times are GMT -4. The time now is 16:10.