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Old   June 3, 2013, 12:08
Default snappyHexMesh refinement
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Giovani Diniz
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Guys, good morning,

I'm new to OpenFoam and I have started my research in propeller design. I'm eager to use OpenFoam as my primary analysis tool and I have made a few improvements using the user's guide.

But, I got stuck with the refinement of my mesh now. I have tried to follow all hints i saw in previous posts but I can't figure out the parameters I have to use to get a smooth mesh.

I attached my SHMDict and the screenshots of my propeller.
For what I know so far, I guess the snapping is not being done properly as the surface is still not smooth.

I also get a message from paraview displaying issues with OpenGL.

If anybody would have a guess would be a huge help.

Thank you
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File Type: jpg Screen Shot 2013-06-03 at 10.22.17 AM.jpg (65.9 KB, 34 views)
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File Type: txt snappyHexMeshDict.txt (3.8 KB, 9 views)
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Old   June 3, 2013, 13:53
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Nima Sam
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it seems it is in castellatedMesh process and no refinement has been done
i suggest to add snappyHesMeshDict from propeller dict in your system
Quote:
tutorials/incompressible/pimpleDyMFoam/propeller
and edit it
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Old   June 3, 2013, 16:50
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Nima, thank you for your insight!

I have changed my shmdict according to the one in the tutorial, but it still doesn't seem to be working properly...

I honestly have no idea where to go now.

Do you know if the geometry needs to be closed? I mean, in my case, I only have the propeller blades with no hub, and in the tutorial there are blades all connected to the hub. Do you think this could the issue?

Another point I noticed is that there are no sharp edges on the leading and trailing edges of the tutorial's geometry. But in mine I do have, 'cause I have a real geometry.

I tried many runs already changing values, but nothing seems to work...
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Old   June 3, 2013, 23:58
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actually, i dont think so,
it seems strange , as i said before it seems it remains at castellatedMesh process, you can post your testcase here, then i can test it for you
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Old   June 4, 2013, 11:47
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Nima, thanks for your support.

Can I send you via e-mail? My .stl file is quite big and the forum doesn' support files that big.

zip files is 184kb but still won't go...
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Old   June 5, 2013, 09:54
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Nima, how are you?

Thanks for your e-mail and support! I'm glad to say that I found my mistake and it was a quite stupid one, actually.

Well, I had checked that error on the log before and saw some posts about bad .stl files. Good thing about it is that I discovered some flaws in my stl writing routines and corrected them.
(I also learned how to use MeshLab, so it was good after all...)

Finally, I went over my files and I found out that the problem was that I was assigning the inlet/outlet regions as "empty" and not patches...
I got mad, but when I saw the mesh finally worked, I was ok...hahaha

anyways, I'll play with the parameters now to try to refine it, 'cause the tips of the blades are not that great yet (not sure if you can see in attachment). But that's for another thread.

Well, I just wanted to let you know what was the solution for the problem, for your future reference, and thank once again for the assist.

I hope you have a good day, mate!
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