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IDProjectCategoryView StatusDate SubmittedLast Update
0000772OpenFOAMBugpublic2013-03-11 15:442014-01-10 10:22
Reporteruser612Assigned Touser4 
PrioritynormalSeverityminorReproducibilityalways
Status resolvedResolutionfixed 
PlatformLinuxOSUbuntuOS Version12.04
Summary0000772: Wrong surface normals with snappyHexMesh's new baffles feature
DescriptionThe new baffles feature of 2.2.0 results in bad patches. The surface normals along a meshed baffle (i.e. a STL-surface) are inconsistent. When snappyHexMesh splits the surfaces to create boundary patches, the faces of one side are spread over the master and the slave patch. Or in other words, the master patch consists of faces which belong to both sides of the split surface. The same is true for the slave patch. Have a look at the pictures for further explanation.
Steps To ReproduceRun the attached example case.
TagsMesh

Activities

user612

2013-03-11 15:44

 

snappyHexMeshBaffles.tar.gz (37,358 bytes)

user612

2013-03-11 15:45

 

1_triSurface_in_blockMesh.png (34,485 bytes)   
1_triSurface_in_blockMesh.png (34,485 bytes)   

user612

2013-03-11 15:46

 

2_patch_normals.png (36,987 bytes)   
2_patch_normals.png (36,987 bytes)   

user612

2013-03-11 15:46

 

3_baffle_master_patch.png (20,486 bytes)   
3_baffle_master_patch.png (20,486 bytes)   

user4

2013-03-19 15:12

  ~0002024

It is the faceType 'boundary' which has problems. The faceType 'baffle' (so not duplicate the points) seems to work ok.

user4

2013-03-25 15:26

  ~0002060

Correct that - it does not work. It does not handle the case of both sides of the baffle not being in a cellZone.

user612

2013-03-25 17:07

  ~0002067

Yes, this was my experience, too. For baffles and for boundaries you will always get wrong surface normals.
This is also true if you split the faceZones created by snappyHexMesh with createBaffles.
As far as I know there is only one way to get continous face normals: create the faceZones based on a faceSet and a *SlaveCells cellSet. By doing this, the flipMap is created correctly. snappyHexMesh doesn't create (correct) flipMaps for faceZones, does it?

user828

2014-01-09 21:08

  ~0002757

Has there been any progress on this topic? I am very interested in a patch that could enable correction of these normals first for a flat baffle ans second for an arbitrarily curved baffle.

user4

2014-01-10 10:22

  ~0002758

Was resolved around October with 7f49b81cb667b1beac833b1d2be6770db4a6d4ad

Issue History

Date Modified Username Field Change
2013-03-11 15:44 user612 New Issue
2013-03-11 15:44 user612 File Added: snappyHexMeshBaffles.tar.gz
2013-03-11 15:45 user612 File Added: 1_triSurface_in_blockMesh.png
2013-03-11 15:46 user612 File Added: 2_patch_normals.png
2013-03-11 15:46 user612 File Added: 3_baffle_master_patch.png
2013-03-11 15:48 user612 Tag Attached: Mesh
2013-03-19 15:12 user4 Note Added: 0002024
2013-03-25 15:26 user4 Note Added: 0002060
2013-03-25 17:07 user612 Note Added: 0002067
2014-01-09 21:08 user828 Note Added: 0002757
2014-01-10 10:22 user4 Note Added: 0002758
2014-01-10 10:22 user4 Status new => resolved
2014-01-10 10:22 user4 Fixed in Version => 2.2.x
2014-01-10 10:22 user4 Resolution open => fixed
2014-01-10 10:22 user4 Assigned To => user4