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Old   November 22, 2015, 23:30
Default Problems with mesh processing
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Saurabh Tandon
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Hi
I am new user in OpenFOAM and I am trying to export a 3D mesh to openfoam. I am been successful in exporting the mesh but the when I run checkmesh I get the following error:

***Boundary openness (-0.00577288 -0.0138324 -0.0075081) possible hole in boundary description.
***Open cells found, max cell openness: 1, number of open cells 794
<<Writing 794 non closed cells to set nonClosedCells
<<Writing 704 cells with high aspect ratio to set highAspectRatioCells
Minimum face area = 0.338918. Maximum face area = 26.1411. Face area magnitudes OK.
***Zero or negative cell volume detected. Minimum negative volume: -39.3144, Number of negative volume cells: 621
<<Writing 621 zero volume cells to set zeroVolumeCells
Mesh non-orthogonality Max: 179.417 average: 89.7196
*Number of severely non-orthogonal (> 70 degrees) faces: 139.
***Number of non-orthogonality errors: 991.
<<Writing 1130 non-orthogonal faces to set nonOrthoFaces
***Error in face pyramids: 2453 faces are incorrectly oriented.
<<Writing 1602 faces with incorrect orientation to set wrongOrientedFaces
***Max skewness = 96.5521, 34 highly skew faces detected which may impair the quality of the results
<<Writing 34 skew faces to set skewFaces

Is is possible for someone to explain these errors. I know very little about meshing or the mathematics of the process. More importantly is it possible to rectify the errors in OpenFOAM or would I have to mesh again?
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Old   November 23, 2015, 07:55
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This seems to be a very bad mesh that probably won't run. Most likely something went wrong during export. You really need to provide more infos in order to get back useful hints!

Did you read https://openfoamwiki.net/index.php/CheckMesh? Have you tried to visualize the mesh using paraview or paraFoam?
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Old   November 26, 2015, 02:06
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Saurabh Tandon
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Hi

Thank you replying to my post. Here is the context of my research. I am trying to use OpenFOAM to do pore scale simulations in rocks for magnetization decay. An example of the geoemtry that I am meshing be seen in this link

https://www.spec2000.net/09-corebasics.htm.

I would like to mesh disconnected geometry and I am not getting good results with cgal or gmsh. I am open to any feedback that you might have about meshing, I have studied the link that you posted below. Thanks again for the help.
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File Type: jpg digitalcore0.jpg (42.1 KB, 10 views)
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Old   November 26, 2015, 02:12
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Saurabh Tandon
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This is my gmsh file. Please chnage the name of the file to gmsh file and run it on s software that can process gmsh files.
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File Type: jpg mesh_pic.jpg (150.6 KB, 13 views)
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File Type: txt Generated_Mesh_test.txt (79.8 KB, 2 views)
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