snappyHexMesh feature edge
Hi all;
I'm trying to mesh a simple circular cylinder but I'm having the classical snappyHexMesh troubles with the free end edge. Now, I saw this news on the openfoam website: http://www.openfoam.com/news/snappyH...ature-edge.php It could help me out a lot. How does that work? Any idea? Could not find anything on the user guide… Thank you! |
Hi lovecraft22,
I was thinking about this myself... It's here: "tutorials/mesh/snappyHexMesh/flange" Keep in mind that you must have at least OpenFOAM 2.0.0! Check the Allrun script on that folder for more details. And next time you want to find a file, here's two example commands: Code:
find . -name "snappy*Dict" Bruno PS: must... stop... drooling.... :p since OpenFOAM 1.5 that people have been waiting for this feature... me included :) |
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Regards Bastian |
Hi Bastian,
OK, to sum up:
Tip - Try running: Code:
surfaceFeatureExtract -help Bruno PS: who needs drugs, when one can drool so easily...... :D |
Thank you wyldckat, can't see any difference though…
I did the same ad the tutorial with my cylinder without any difference with or without the feature edge… |
Did you manage to get it working with nice results?
Any way to check whether the edge was picked up correctly? Paraview doesn't seem to like this .eMesh file… |
5 Attachment(s)
Attached are a few pictures showing details about the snapped edges...
Note: I'm not using the official OpenFOAM mesh reader for ParaView, I'm using the internal reader in ParaView 3.8.0... so there might be some referential discrepancies, therefore that might be the reason why the STL seems a bit offset from the resulting mesh. edit: there's plenty of files with info about the edges, but currently I have no clue how to visualize them. I haven't built the official plug-ins yet, so I haven't check them yet either :( edit2: Just tested with the official plugins and I've confirmed that the snapping isn't perfect, so the attached pictures are validated. There might be some tolerance variable somewhere... or additional refinement is necessary. Best regards, Bruno |
Bruno,
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This is old staff. This eMesh file is used to refine to a specified level (0 in your case which means no refinement at all) at all explicit feature edges given in the file. This has already been possible before. I think the following parameter is the one, did you use it in your test? Code:
//- Highly experimental and wip: number of feature edge snapping Regards Bastian |
Greetings to all!
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This application can be used to open ".obj" files, as indicated here: Quote:
I haven't tested JavaView yet... hopefully it might open eMesh files as well... but I doubt it, since last I looked, it was an OpenFOAM format. @Bastian: Quote:
Best regards, Bruno |
Yu can load the .obj files in paraview…
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Here's the difference between having it set to 10 (on the left) and having it commented out (on the right): http://dl.dropbox.com/u/2459663/Senza%20titolo.jpg |
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Regards Bastian |
I can see the pictures, try opening the url directly.
I haven't tested without the eMesh file. I'll do that when I'll get back home in 10 hours al let you know. |
I commented out these lines
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{ |
Greetings to all!
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Ah, and the directory listing can also help get our attention on some more genuine pearls: http://foam.sourceforge.net/docs/cpp/dirs.html Quote:
Best regards, Bruno |
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Regards Bastian |
I made a post-and-run yesterday so I didn't give any details, nor did I have a compiled OpenFOAM 2.0.0/x at hand.
Now that I have a build at hand and a bit more time:
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All I know is that from the tutorial we can easily have access to the edges used by snappyHexMesh, namely:
Best regards, Bruno |
5 Attachment(s)
Hi there!
I am new to OpenFOAM and tried my very best but I stuck at a question about snappyHexMesh which could belong to this thread. What I am trying to do for a first step is to build a triangular geometry which later will be used to construct a rod bundle geometry. But unfortunately as you see in the pictures I attached there is a problem with sharp edges. What I tried: - with and without featureEdgeRefinement - gave it a try with a slightely modified geometry (rounded edges -> see picture) - tried to adjust a lot of parameters in the snappyHesMeshDict (without success) -I created the .stl by myself but also tried an CAD export without improvements. - checked my boundary file: inlet and outlet are empty while the sides of my block are set as wall boundaries. I found a thread from last year which is about a tool called snapEdge. But in case I got that right, by now OF2.0.1 (which I use) originaly brings those functions. So there is no need for snapEdge anymore. Please correct me if I am wrong. :-) I hope I provided all relevant information and am looking forward for any tips and hints. Thank you in advance :-) cheers Sebastian snappyHexMeshDict: Attachment 10391 Pictures: Attachment 10387 Attachment 10388 Attachment 10389 Attachment 10390 |
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Regards Bastian |
Greetings to all!
@Sebastian: My guess is that surfaceFeatureExtract didn't give you a good ".eMesh". A bad angle will result in bad line references for snapping :( Open the ".obj" files in ParaView, namely the ones that were placed in your case folder after running surfaceFeatureExtract. Check if there are any/all necessary lines for actually snapping the edges ;) If not, try another angle! Best regards, Bruno |
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