CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > CFX

Penetrating elements in extruded mesh

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

LinkBack Thread Tools Search this Thread Display Modes
Old   May 20, 2005, 04:08
Default Penetrating elements in extruded mesh
Michael P
Posts: n/a
Hello, I have a problem with a mesh I created with ICEmCFD5.1. I will briefly describe the mesh: I start off by meshing a plane rectangulare surface with a triangular surface mesh. This 2d-domain is 38x38 Meters big, the element size is 6000mm at each curve. Then, this Mesh is extruded along a vector into the third dimension with 28 layers, each 1.25 mm thick. The resulting 3d-mesh is well-adapted to the surrounding geometry (a cuboid), which means that the extruded surface elements "arrive" exactly at the opposing surface of the cuboid. All resulting shell elements are assigned to the proper geometric families (all shells in different families, all volumic elements in a seperate family).

The problem: Grid check gives "duplicate elements", which appear only at one curve of the original rectangle (the rectangle which was first meshed in 2d) and a few elements (about 10 elements of about 170) of the of the adjactant surface which is produced by the extrusion. Running this mesh in FLUENT causes a divergence because of these elements, who cause abnormal high velocities (10exp7 m/s with an inlet velocity of 40 m/s) and pressures.

By zooming into the region, where the problematic elements are displayed, no actual interference between different surface elements is visible. Plus, all elements have been created by extrusion, so how can they penetrate? What are possible solutions?

Thanks in advance, Michael
  Reply With Quote

Old   May 20, 2005, 04:18
Default Re: Penetrating elements in extruded mesh
Posts: n/a
do you have access to gambit, if you have you can do one simple thing, read the mesh into gambit, if you see some arbit facet delete them and re-export the mesh, this time it shall be clean, (i am assuming that if u can read the mesh into fluent u can also read the same mesh into gambit , by its import).
  Reply With Quote

Old   May 20, 2005, 08:06
Default Re: Penetrating elements in extruded mesh
Michael P
Posts: n/a
Hi zxaar,

the problem is, that I'm writing a script, which shall create tehe geometry and the mesh. So, unfortunately, its no use to exprot and reimport the mesh with gambit, as it makes the automatisation much more less practicable.

I found by try&error, that some spacings for the extrusion cause the mesh to have these bad elements, while other spacings give good meshes, all on the same geometry and all with the same original 2d-mesh.

however, thanks for the help!
  Reply With Quote


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
Fluent dynamic mesh 'remeshing' method for pyramid elements DarrenC FLUENT 14 December 11, 2015 04:58
[ICEM] Generating Mesh for STL Car in Windtunnel Simulation tommymoose ANSYS Meshing & Geometry 48 April 15, 2013 04:24
MESH ERROR Francesco - University of Florence, Italy CFX 2 April 24, 2008 11:10
Merging mesh elements in ICEM Felix CFX 1 May 9, 2007 10:33
CFX4.3 -build analysis form Chie Min CFX 5 July 12, 2001 23:19

All times are GMT -4. The time now is 16:01.