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IDProjectCategoryView StatusLast Update
0000696OpenFOAMBugpublic2012-12-07 14:11
ReportermartinB Assigned Touser4 
PrioritylowSeveritytrivialReproducibilityalways
Status resolvedResolutionfixed 
PlatformLinuxOSOpenSUSEOS Version12.1
Summary0000696: Collapsing edges in extrudeMesh destroys mesh
DescriptionIf a mesh contains very large and very small elements the collapsing of edges destroys the resulting mesh from the extrudeMesh utility.

Output of the utility is:
"""
...
Collapsing edges < 2e-05 ...

Merging edge (0 1) since length 1.56918194e-05 << 2e-05
Merging edge (0 11) since length 2.19605425e-06 << 2e-05
...
Cell:0 uses faces:6(0 1 2 3 4 350500) of which too many are marked for removal:
    0 1 2 3 4 350500
Cell:1 uses faces:6(5 6 7 8 350583 0) of which too many are marked for removal:
    5 6 7 8 350583 0
...
"""

As a workaround line 669 in extrudeMesh.C can be modified from
    const scalar mergeDim = 1E-4 * bb.minDim();
to
    const scalar mergeDim = 1E-12 * bb.minDim();

If the collapsing edges feature should not be removed completely, an additional option "-noEdgeCollapsing" would be useful, may be with a value for the relative size factor.
Steps To Reproduce- untar the attached archive "big_to_small_tube.tar.gz"
- run blockMesh
- run extrudeMesh
--> Failure
After modification of extrudeMesh.C the mesh extrusion works perfectly.
TagsNo tags attached.

Activities

martinB

2012-12-06 14:21

reporter  

user4

2012-12-07 14:11

  ~0001814

I've pushed a user setting for the tolerance in 21x to extrudeMesh. See the extrudeMeshDict in the source directory.

commit 840bd62f110a572fc216676c2451f10b3cdc89ca

Thanks for reporting.

Issue History

Date Modified Username Field Change
2012-12-06 14:21 martinB New Issue
2012-12-06 14:21 martinB File Added: big_to_small_tube.tar.gz
2012-12-07 14:11 user4 Note Added: 0001814
2012-12-07 14:11 user4 Status new => resolved
2012-12-07 14:11 user4 Fixed in Version => 2.1.x
2012-12-07 14:11 user4 Resolution open => fixed
2012-12-07 14:11 user4 Assigned To => user4