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Vidya Raja October 6, 2005 12:26

Subtracting volumes imported from ProE
Hi, I have a solid geometry imported from ProE. I created a cylinder (which mimics a tube) in GAMBIT and then tried to subtract the volume of the solid from that of thecylinder to get the flow domain within and around the solid. But I always get an error message which says: CAN'T OPERATE ON VOLUME (the solid) WITH NON- REAL GEOMETRY. What does this mean and how can I fix this problem?

I tried several ways of import from ProE- IGES, STEP, Parasolid.

But nothing works. Can someone help?

Thanks, Vidya

Renato October 6, 2005 12:49

Re: Subtracting volumes imported from ProE
Hi Vidya

Are you sure you have imported the solid volume? Sometimes the software is able only to reconstruct the surfaces of the geometry.

If your geometry is complex try to check if you've got topologic degeneracy because of the tolerance when importing models.



Vidya Raja October 6, 2005 14:03

Re: Subtracting volumes imported from ProE
Hi Renato, Thanks for the reply. I imported the solid from ProE as a Parasolid. And I also tried as STEP file. But still I get the same messages.

Also after subtraction, will FLUENT consider the entire set- up as a single entity?

Regards Vidya

Renato October 6, 2005 14:38

Re: Subtracting volumes imported from ProE
I'm not used with Gambit/Fluent's capabilities when working with solid models, but I've already modeled with other preprocessors (Patran... I hate Patran, Cubit and Ansys - Ansys is my favorite). Most of the preprocessors have problems in importing/exporting models among them just because the model tolerance and numerical representation/truncation. I could say that in Ansys the IGES format works fine most of the time when your model is not too complex. With complex models Ansys returns messages like that you have described and you are obligated to "simplify" the model by partitioning it in some minor blocks and operating them one by one or by reconstructing the parts that were lost (sometimes it's hard to be done). In Ansys there are several ways to cut volumes (with the working plane, an area, etc...). It's helpful also when you are meshing a large and complex model in a limited computer system.

By the way, if your original solid model (in ProE) is not "glued" yet you could try to export/import it in minor part and subtract these parts one by one.



Andrew Hayes October 6, 2005 15:06

Re: Subtracting volumes imported from ProE
If I remember correctly, when I have brought drawings in from SolidWorks I always had to HEAL the geometries, or define the faces etc in GAMBIT.

Arunvel October 7, 2005 09:52

Re: Subtracting volumes imported from ProE
I would kind of back up the same thing, From ProE its better to get it on to Ansys and do 1.Vovlap 2. Repair Geometry. (ProE to Anasys) doesnot need any parasolid/other stuff to be done. Then this geometry is Ansys is compatible for both CFX and Fluent with not much repairing (ofcourse parasolid need to be generated)

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