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SHM not snapping

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Old   January 20, 2013, 18:50
Default SHM not snapping
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David Gaden
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snappyHexMesh is castellating (refining) but it is not snapping to the surface, no matter what I try to do.

When my own geometries didn't work, I tried the pipeBend tutorial suggested on the SwiftSnap page ( http://openfoamwiki.net/index.php/Contrib/SwiftSnap ). The result is shown in the attachment.

I also tried the "cylinderCase" described on this wiki ( https://sites.google.com/site/snappy.../cylinder-case ), and the result is also attached.

This has been tried in OF2.1-x and OF1.6-ext.

To me, this tells me the case setups are correct, but there's something not working on my machine. Perhaps some geometric-based dependency is improperly installed or something... I am working on Linux Mint XFCE.

That is my tale of woe.

Does anyone have any suggestions?

-Dave
Attached Images
File Type: jpg pipeBendTutorial.jpg (85.4 KB, 17 views)
File Type: png cylinderCaseWiki.png (21.9 KB, 10 views)
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Old   January 20, 2013, 19:41
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Alberto Passalacqua
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Hi Dave,

I have modified the cylinder case because it did not take advantage of the surface features, and changed a few settings in snappyHexMeshDict (taken from the flange tutorial). Could you please run the case with ./Allrun and see what happens, so we have a common reference? You find a screenshot of the result I obtained attached.

Best,
Attached Images
File Type: jpg cylinder.jpg (76.9 KB, 16 views)
Attached Files
File Type: gz cylinder_case_ap.tar.gz (61.6 KB, 5 views)
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Old   January 20, 2013, 23:06
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David Gaden
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Thanks Alberto,

I ran your case, and the result did snap. It looks like the image you attached. So that raises the question: what am I doing wrong?

I did a diff between the two case directories, and I think my mistake is exactly what you tweeted me about:
Quote:
Alberto Passalacqua ‏@albertop78 @DavidGaden Did you forget to use surfaceFeatureExtract or to include the emesh? :-)
Mind you, the pipe bend tutorial was using the emesh...

So I will use your case as a template and report back tomorrow with the results!

Thanks again!

-Dave
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Old   January 20, 2013, 23:19
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Alberto Passalacqua
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OK. Let me know :-)
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Old   January 22, 2013, 21:37
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David Gaden
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Thanks for the assistance, Alberto.

So I got your case working, but I still can't seem to get mine working. Maybe you can tell me what I'm doing wrong (if you have the time)?

I've attached the case file, and the blender file is available here for the next few weeks:

https://dl.dropbox.com/u/18048766/Un...Reactor2.blend

The result I get is shown in the attached picture.
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File Type: png Reactor.png (53.6 KB, 20 views)
Attached Files
File Type: gz reactor.tar.gz (30.0 KB, 2 views)
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Old   January 23, 2013, 00:02
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Alberto Passalacqua
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Hi Dave,

I attach a case that seems to work. Major changes:

- added all the stl files to the eMesh creation (there were typos and not removing the log the last 4 files were not generated by the ./Allrun script)

- refined blockMesh box

- changed surfaceFeatureExtract angle to 150

Check the mesh quality to be safe, and in case it's not good enough, I'd refine the blockMesh box.

Best,
Attached Files
File Type: gz reactor.tar.gz (25.1 KB, 8 views)
marupio and atg like this.
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Old   January 23, 2013, 22:03
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David Gaden
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Wow! Thanks so much, Alberto! That is an awesome mesh.

It would be embarrassing to admit how long I've been struggling with this. This also was standing in the way of my final simulation for my PhD. (All the other meshes were simple cubes, so it was easy to just use blockMesh.)

As far as I can see, my mistakes were little typos with the feature extract command, and I didn't include all the eMesh files.

Thank-you so much!

-Dave
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Old   January 23, 2013, 22:28
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Alberto Passalacqua
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Quote:
Originally Posted by marupio View Post
Wow! Thanks so much, Alberto! That is an awesome mesh.
Welcome.

Quote:
As far as I can see, my mistakes were little typos with the feature extract command, and I didn't include all the eMesh files.
Yes, that was it, and some tweaking of the angle.

Best,
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