CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Mesh Generation & Pre-Processing Software > enGrid

Volume mesh - crashing - Netgen: Geosearch

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   August 19, 2014, 16:30
Exclamation Volume mesh - crashing - Netgen: Geosearch
  #1
Member
 
Gowain
Join Date: May 2014
Location: Ireland
Posts: 86
Rep Power: 12
eaglemckenna is on a distinguished road
Hi
can someone explain the netgen geosearch error-i have been having trouble with this for a number of days now: I have simplified my geometry aswell as improved the mesh in an effort to resolve this - indeed, I can create a prismatic layer prior to surface meshing but not after - and I can not surface mesh after I have a prismatic layer, so perplexed.
See geometry below for idea of case;
any info on such errors would be great - indeed it would be a help if such error messages were more informative -
hopefully get it later - does engrid core dump on low slower machines ?
kindrgds
g
Attached Images
File Type: jpg Screenshot from 2014-08-19 20_09_20.jpg (84.0 KB, 41 views)

Last edited by eaglemckenna; August 19, 2014 at 18:12.
eaglemckenna is offline   Reply With Quote

Old   August 19, 2014, 18:32
Lightbulb :)
  #2
Member
 
Gowain
Join Date: May 2014
Location: Ireland
Posts: 86
Rep Power: 12
eaglemckenna is on a distinguished road
Think i have it now - must have been something to do with my terrible meshing up near inlet and outlet points in the domain ^ haha
eaglemckenna is offline   Reply With Quote

Old   August 20, 2014, 13:44
Default
  #3
Senior Member
 
M. C.
Join Date: May 2013
Location: Italy
Posts: 286
Blog Entries: 6
Rep Power: 17
student666 is on a distinguished road
Hi,
I'm very interested in engrid, but one thing stops me is something I red somewhere, sorry I don't remember... anyway it was said that you have to define for all faces, a patch_name, or during meshing the sharped edges will be smoothed if same patch holds two connected faces. is it true? is there a workaround?
student666 is offline   Reply With Quote

Old   August 21, 2014, 11:59
Talking reply to student666
  #4
Member
 
Gowain
Join Date: May 2014
Location: Ireland
Posts: 86
Rep Power: 12
eaglemckenna is on a distinguished road
Hi
I created my model and assigned the patches within blender prior to exporting into engrid - engid surface and volume mesing does not smooth out sharp edges between patches, i.e "front" and "left1" or "top2" and "right".
Overall I would say engrid is a great tool and most problems can be worked around when modelling with blender.
kind rgds
g
eaglemckenna is offline   Reply With Quote

Old   August 29, 2014, 04:57
Default
  #5
Senior Member
 
M. C.
Join Date: May 2013
Location: Italy
Posts: 286
Blog Entries: 6
Rep Power: 17
student666 is on a distinguished road
Hi,

I'm trying to setup a test case ( a cube ) to learn how to use engrid, I generated the stl file into Salome, then I Imported the STL file into blender.

I installed the add ons as for the following thread http://www.cfd-online.com/Forums/eng...er-2-69-a.html

I exported the file for engrid, but I get this message:

Code:
 p, li { white-space: pre-wrap; }  smallest edge length is 1e+99
 secs. for IOOperation: 2
 deleting Operation 0x24f61c0
can you help me with this?

thanks a lot

PS: I'm using blender 2.71

Last edited by student666; August 29, 2014 at 06:34.
student666 is offline   Reply With Quote

Old   August 29, 2014, 11:38
Arrow reply to student666
  #6
Member
 
Gowain
Join Date: May 2014
Location: Ireland
Posts: 86
Rep Power: 12
eaglemckenna is on a distinguished road
Mmmm
You should just work inside blender and make a cube:
1 - make sure cube is sized correctly 2mx2mx2m is default and is ok.
2 - make sure cube is water tight
3 - make sure normals point away from fluid (edit mode press w for menu)
3 - assign patches inside blender (edit mode face selection P assign selection)
4 - select all of the cube and patches inside edit mode and export into engrid .begc file
5 - open with engrid and strike C to check mesh

rgds
g
eaglemckenna is offline   Reply With Quote

Old   August 29, 2014, 20:52
Default
  #7
Senior Member
 
M. C.
Join Date: May 2013
Location: Italy
Posts: 286
Blog Entries: 6
Rep Power: 17
student666 is on a distinguished road
Hi G,

if I start from blender and follow the instruction:

https://github.com/enGits/engrid/wik...ting_the_Model

by working with blender all goes to an happy ending. But my request for help comes from complex geometry.

Now I would like to test engrid in order to verify if it is easier to add layers as with SnappyHexMesh is quite hard.
Normally I model the CAD geometry and export the .stp file to Salome, then I generate single stp file according to my patches, then in gmsh I import and mesh once again for a good quality of the stl and export to OF as stl.


I thought it was possible to follow same workflow, and to import stl files in blender (after gmsh) and export into Engrid for meshing. But even for the simplest case (the cube) I get the error above.

any other suggestion?
student666 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
sliding mesh problem in CFX Saima CFX 46 September 11, 2021 08:38
[ICEM] Negative volume error in hybrid mesh siw ANSYS Meshing & Geometry 4 September 3, 2014 06:25
Problem of simulating of small droplet with radius of 2mm liguifan OpenFOAM Running, Solving & CFD 5 June 3, 2014 03:53
Negative Volume during Mesh Motion Analysis giov_ingr FLUENT 2 December 13, 2013 07:09
On the damBreak4phaseFine cases paean OpenFOAM Running, Solving & CFD 0 November 14, 2008 22:14


All times are GMT -4. The time now is 10:37.