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2015-03-13 13:22
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Greetings MHB, This issue looked familiar to me. I suspect you're not using a recent version of OpenFOAM, because "mergeMeshes" can be used with "-overwrite" since... I think since OpenFOAM 2.1. This and other related details are addressed here: http://www.cfd-online.com/Forums/openfoam-meshing-utilities/113863-when-can-stitchmesh-used.html The solution to your case is to use "-perfect" in the second run of "stitchMesh". As for stitching it all at once, this is also explained on that thread and on this bug report: http://www.openfoam.org/mantisbt/view.php?id=347 As for the message itself... I'm not sure if "-partial" should be upgraded to support scenarios where the mesh perfectly overlaps. Best regards, Bruno |
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2015-03-16 15:50
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Hi Bruno, Thank you very much for your guidance. Yes it works fine with replacing option partial with perfect for stitchMesh. But I think it does not work for more complicated cases. The case I already attached was for explaining the problem. After applying your solution to the real case that I am working on it I see that it does not work although the situation is the same. Please see the new file attached. In the real case I have six blocks. Before the final step, I generate a block consisted of five smaller blocks and everything is fine without any error and checkMesh reports OK. But at the final step when I want to cover the mentioned rectangular block generated from the previous steps by a larger block having a rectangular hole, stitchMesh gives error even though I use “perfect” option for that. If possible, could you please check it as well? Best regards, Mohammad |
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why_perfect_will_not_work.png (35,806 bytes) |
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Hi Mohammad, The "-perfect" option will not work because of what's shown in the attached picture "why_perfect_will_not_work.png". For this, the "-partial" option would have to be used, but the problem is that the algorithm is not prepared to handle such this scenario; it can handle stitching 3 of the 4 internal sides in the last operation, but the 4th side will lead to the error you've gotten. You can try splitting the last big mesh into 2 or 4 parts, so that you can stitch each big part individually and then finally stitch these big parts to each other... it could work, because the final stitches would be connecting the internal block to the external block, therefore making the algorithm more aware of what needs to be done. I'll put up a drawing in a few minutes on what I'm referring to. Because the problem with the current algorithm is that it sort-of goes around in a loop trying to close the final internal patches, but it gets lost when it can't find an end in the direction it's looking, probably because there is no connection to the external patch. I would say that fixing this issue in the algorithm falls into the category of a feature request, because this isn't exactly a common requirement for stitchMesh. Best regards, Bruno |
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example.png (60,764 bytes) |
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In the attached image "example.png" is one possible configuration, so that you stitch each one of the 4 green blocks to the internal pipe and only after that should you stitch between each one of the green blocks. |
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Feature request requiring funding or code contribution. |
- Anonymous
