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[ICEM] Geometry Tolerance and meshing

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Old   May 26, 2011, 17:01
Default Geometry Tolerance and meshing
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Claudio
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Hello there.
I worked for the past 2 months on the meshing of a very complex centrifugal compressor. After many days of frustration with Icem I managed to have a clean and smooth structured mesh of the geometry. However, whenever I try to refine it, I have negative determinants everywhere .

I am trying to do a CFD simulation of a high pressure compressor with supercritical CO2. The Re is very high and the estimated cell size in order to have a reasonable y+ near the wall is between 1 and 0.1 microns .

I tried to repair the geometry several times with icem, but even if I set the model tolerance and triangulation tolerance to 10^-07 I still can not fix it. Moreover, since Icem lacks of proper methods to define periodic planes, I had to manually crate all the periodic boundaries. Needless to say that all the geometric entities I created share the same tolerance of the geometry.

Is there anybody who can help me? Does anybody have any experience with this kind of issue?

thanks
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Old   June 6, 2011, 07:34
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jeevan kumar
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If you can upload the tetin and the blocking file then i will have a look and can suggest you.

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jeevan
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Old   June 6, 2011, 09:33
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why don't you use turbogrid to mesh your compressor?
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Old   June 6, 2011, 10:03
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Claudio
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Hello there!!!
Thank you very much for the reply.

Unfortunately I am not allowed to disclose any of the geometry file as they belong to the industrial sponsor . Very sad, I know. Is there any way I can provide some information without giving up rights on the geometry file? In particular, I was trying to generate planes and lines in Icem. Even if I specify very small tolerance I can still see that lines and surfaces are not perfectly matching. Even if I keep tolerance to 10e-07 I can't refine the mesh to 10e-06 without having cells falling into the gaps.

I actually thought about Turbogrid... but I am not sure how I can generate the initial file to be imported: The geometry I am working on is fairly complicated with seal passages and leakage flows. I have a STEP and parasolid file of the whole geometry. How do I generate the initial file to be imported in Turbogrid?

Thanks a lot for your help!!!
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Old   January 1, 2012, 12:51
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