CFD Online Logo CFD Online URL
Home > Forums > CFX

Importing format (Help!)

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

LinkBack Thread Tools Display Modes
Old   April 3, 2003, 00:07
Default Importing format (Help!)
Posts: n/a
I realise that CFX allows quite a number of CAD formats to be imported to Build. I wonder if there's any difference between these formats? E.g. will importing step or sat file be better than importing iges file?

Another issue: Has anyone ever imported the mesh generated by Fluent Gambit to Build before? Will there be a problem if you do so?

Thanks in advance for giving me advice.
  Reply With Quote

Old   April 3, 2003, 18:25
Default Re: Importing format (Help!)
Glenn Horrocks
Posts: n/a
Hi Dany,

I'm no expert on CAD import, but here's my experience:

1) IGES is just an approximation to the geometry. In simple geometries (ie straight lines, circles etc) IGES works very well, but for complex geometries with compound curvature IGES causes surfaces edges not to match and other nasty stuff. It is very sensitive to the mobel global tolerance.

2) Parasolid is an exact representation of the geometry (if it comes from a parasolid based CAD system!). However not all parasolid is the same, and you will notice that some CAD systems import better into Build than others. You will still need to do some clean-up work on complex geometries. It has some sensitivity to the global tolerance.

3) STEP and SAT files are alternatives, but I had problems getting the ACIS-SAT license working for me (but I found the parasolid license which comes with it worked OK for me so it was OK). I have no experience with the quality of geometry from these methods.

4) You would think the CAD-specific formats (eg UG, ProE etc) would be the best. However, as most of these CAD systems use parasolid as the basic geometry description I cannot see how these would be much better than parasolid, but I've never tried them.

5) There is basic geometry representation in the Patran Neutral format, but I think it can only handle flat surfaces and simple circles and the like. It will not include any surfaces more complex than that. The main of this format is to import the mesh rather than the geometry.

Has anybody else got experience here, especially points 3) and 4)? If you are dealing with complex geometries, you will be spending a significant proportion of your time fixing geometry problems so Build can use it, so this is an important issue.

Regards, Glenn Horrocks
  Reply With Quote


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
NASTRAN Data format Srinivasan Arunajatesan Main CFD Forum 1 January 2, 2014 07:20
Best format for simulation data? cbisw Main CFD Forum 9 May 30, 2011 02:38
Problem importing mesh gambitToFoamfluentMeshToFoamstarToFoam dmoroian OpenFOAM Other Meshers: ICEM, Star, Ansys, Pointwise, GridPro, Ansa, ... 0 November 24, 2005 16:35
Format for importing Plot3d files into Star-CCM+ Meredith Siemens 1 October 12, 2005 12:28
Importing dxf file format Jonathan FLUENT 2 March 25, 2004 06:25

All times are GMT -4. The time now is 16:53.