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-   -   CAD model sliver faces - CFX Mesh - Parasolid? (http://www.cfd-online.com/Forums/cfx/26991-cad-model-sliver-faces-cfx-mesh-parasolid.html)

Ianto February 5, 2009 06:17

CAD model sliver faces - CFX Mesh - Parasolid?
 
Dear All,

I'm using CFX mesh and have had problems with sliver edges on every Solidworks model I've analysed. Having some experience with Solidworks, I also realise how difficult it is to produce a model of any complexity without their appearance somewhere along the way.

Combining slivers into larger virtual faces in Mesh circumvents the problem, but is a very slow process as the virtual faces themselves can cause problems with meshing - the best approach to creating them is to attempt a mesh after each new virtual face (and only combine two faces at a time). This way if a virtual face is causing a problem it can be identified and deleted easily, otherwise you have to go through a process of elimination - deleting one at a time, and in fact, I've had to delete all in the past and start again as the problem can be impossible to track down.

Needless to say this is a painstaking process and very time consuming.

It's been suggested that saving the model as a parasolid before importing to CFX Mesh might help as it removes the history of how the CAD model was built, and the sliver faces with it - the model just becomes one solid lump as I understand it. I wondered if anyone has any experience/thoughts on this, or indeed any other suggestion to speed up the meshing process?

Many thanks,

Ianto

cfdguy February 5, 2009 14:40

Re: CAD model sliver faces - CFX Mesh - Parasolid?
 
CAD clean up and Meshing usually take about 60% all the work on industry problems, unfortunately.

When I started on Pro-Engineer I used to need some virtual topology in Workbench. Now, I don't need them anymore. I think it is much easier when you fix things inside the CAD program. Much hard work, though.

Parasolid, IGES, etc, are all representations of the model coming from the CAD program. They can't help you when the 1st is not suitable for a CFD mesher.

Cheers!

Ianto February 6, 2009 04:03

Re: CAD model sliver faces - CFX Mesh - Parasolid?
 
Ah, okay... I guess there's room for improvement on the CAD technique front then but I can still expect to spend a lot of time repairing models!

Thanks for you response.

Ianto

Glenn Horrocks February 8, 2009 19:32

Re: CAD model sliver faces - CFX Mesh - Parasolid?
 
Hi,

In workbench use the patch independant mesher. It is ideal for messy CAD. If that does not have enough options consider going to ICEM. It is the best mesher available for messy CAD and handles it far better than WB.

Glenn Horrocks


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