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April 7, 2008, 05:48 
Hallo,
I created a mesh wit

#1 
New Member
Anita K.
Join Date: Mar 2009
Posts: 25
Rep Power: 9 
Hallo,
I created a mesh with blockMesh and m4. Now I want to mirror the mesh at xaxis. I used mirrorMesh. I worked, but the mesh points on the mirror plane are vanished. As result the cells on the mirror plane become bigger. Also checkMesh reacts strange. Anita original mesh: mirrored mesh: CheckMesh: Exec : checkMesh . 2D Date : Apr 07 2008 Time : 11:42:38 Host : st31 PID : 6301 Root : /home/kienzani/OpenFOAM/kienzani1.4.1/run/ownTests/VortexVersuch1 Case : 2D Nprocs : 1 Create time Create polyMesh for time = constant Time = constant Mesh stats points: 26366 edges: 65327 faces: 51852 internal faces: 25488 cells: 12890 boundary patches: 7 point zones: 0 face zones: 0 cell zones: 0 Number of cells of each type: hexahedra: 12890 prisms: 0 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 0 polyhedra: 0 Checking topology... Boundary definition OK. Point usage OK. Upper triangular ordering OK. Topological cell zipup check OK. Face vertices OK. Faceface connectivity OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces ... Patch Faces Points Surface inlet 65 132 ok (not multiply connected) outlet 57 116 ok (not multiply connected) outer 220 442 ok (not multiply connected) body 52 106 ok (not multiply connected) front 12890 13183 ok (not multiply connected) backside 12890 13183 ok (not multiply connected) mirror 190 384 ok (not multiply connected) Checking geometry... Domain bounding box: (0.03 0 0.0005) (0.12 0.03155 0.0005) Boundary openness (9.1555e19 2.28887e17 2.22228e14) OK. Max cell openness = 1.97984e16 OK. Max aspect ratio = 4.60698 OK. Minumum face area = 1.30098e07. Maximum face area = 2.14313e06. Face area magnitudes OK. Min volume = 1.30098e10. Max volume = 1.17683e09. Total volume = 4.4956e06. Cell volumes OK. Mesh nonorthogonality Max: 9.75454 average: 1.3819 Nonorthogonality check OK. Face pyramids OK. Max skewness = 0.159581 OK. Min/max edge length = 0.000288467 0.00214313 OK. All angles in faces OK. Face flatness (1 = flat, 0 = butterfly) : average = 1 min = 1 All face flatness OK. Mesh OK. > FOAM Warning : From function polyMesh::readUpdateState polyMesh::readUpdate() in file meshes/polyMesh/polyMeshIO.C at line 211 Number of patches has changed. This may have unexpected consequences. Proceed with care. Time = 0 Mesh stats points: 51722 edges: 128523 faces: 102888 internal faces: 51792 cells: 25780 boundary patches: 6 point zones: 0 face zones: 0 cell zones: 0 Number of cells of each type: hexahedra: 25780 prisms: 0 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 0 polyhedra: 0 Checking topology... Boundary definition OK. Point usage OK. ***Faces not in upper triangular order. <<Writing 1 unordered faces to set upperTriangularFace Topological cell zipup check OK. Face vertices OK. Number of identical duplicate faces (baffle faces): 617 Faceface connectivity OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces ... Patch Faces Points Surface inlet 128 258 ok (not multiply connected) outlet 110 222 ok (not multiply connected) outer 440 884 ok (not multiply connected) body 98 196 ok (not multiply connected) front 25160 25548 ok (not multiply connected) backside 25160 25548 ok (not multiply connected) Checking geometry... Domain bounding box: (0.03 0.03155 0.0005) (0.12 0.03155 0.0005) Boundary openness (2.09395e18 3.87209e17 6.31716e14) OK. ***High aspect ratio cells found, Max aspect ratio: 3.2548e+193, number of cells 310 <<Writing 310 cells with high aspect ratio to set highAspectRatioCells Minumum face area = 1.30098e07. Maximum face area = 2.5e06. Face area magnitudes OK. Min volume = 2e300. Max volume = 1.75e09. Total volume = 9.0932e06. Cell volumes OK. Mesh nonorthogonality Max: 180 average: 14.5294 *Number of severely nonorthogonal faces: 362. ***Number of nonorthogonality errors: 813. <<Writing 1175 nonorthogonal faces to set nonOrthoFaces ***Error in face pyramids: 1860 faces are incorrectly oriented. <<Writing 1433 faces with incorrect orientation to set wrongOrientedFaces #0 Foam::error::printStack(Foam:stream&) in "/home/kienzani/OpenFOAM/OpenFOAM1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #1 Foam::sigFpe::sigFpeHandler(int) in "/home/kienzani/OpenFOAM/OpenFOAM1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #2 Uninterpreted: [0xffffe420] #3 Foam::primitiveMesh::checkFaceSkewness(bool, Foam::HashSet<int,> >*) const in "/home/kienzani/OpenFOAM/OpenFOAM1.4.1/lib/linuxGccDPOpt/libOpenFOAM.so" #4 Foam::checkGeometry(Foam::polyMesh const&, bool, bool) in "/home/kienzani/OpenFOAM/OpenFOAM1.4.1/applications/bin/linuxGccDPOpt/checkMesh" #5 main in "/home/kienzani/OpenFOAM/OpenFOAM1.4.1/applications/bin/linuxGccDPOpt/checkMesh" #6 __libc_start_main in "/lib/libc.so.6" #7 Foam::regIOobject::readIfModified() in "/home/kienzani/OpenFOAM/OpenFOAM1.4.1/applications/bin/linuxGccDPOpt/checkMesh" 

April 7, 2008, 07:35 
Problem solved !
I had to c

#2 
New Member
Anita K.
Join Date: Mar 2009
Posts: 25
Rep Power: 9 
Problem solved !
I had to change planeTolerance in mirrorMeshDict from 1e3 to 1e4. Now the mesh looks good. 

July 8, 2008, 01:58 
hello,
where can we find th

#3 
New Member
nikhil babu madduri
Join Date: Mar 2009
Posts: 17
Rep Power: 9 
hello,
where can we find this "mirrorMeshDict" file? replies will be highly appreciated. Thanks Nikhil 

November 9, 2009, 10:22 
same error with makeAxialMesh

#4 
New Member
Vasu
Join Date: Oct 2009
Posts: 17
Rep Power: 8 
Hi,
I'm a novice with OpenFOAM and CFD in general. So any help would be appreciated. I'm getting the same error when I run a checkMesh on my grid after using the makeAxialMesh utility. Can anyone shed some light on this? Here is the output I get. Create polyMesh for time = 0 Time = 0 Mesh stats points: 882 internal points: 0 faces: 1640 internal faces: 760 cells: 400 boundary patches: 3 point zones: 0 face zones: 0 cell zones: 0 Overall number of cells of each type: hexahedra: 400 prisms: 0 wedges: 0 pyramids: 0 tet wedges: 0 tetrahedra: 0 polyhedra: 0 Checking topology... Boundary definition OK. Point usage OK. Upper triangular ordering OK. Face vertices OK. Number of regions: 1 (OK). Checking patch topology for multiply connected surfaces ... Patch Faces Points Surface topology movingWall 20 42 ok (nonclosed singly connected) fixedWalls 60 122 ok (nonclosed singly connected) frontAndBack 800 882 ok (nonclosed singly connected) Checking geometry... Overall domain bounding box (0 0 0.005) (0.1 0.1 0.005) Mesh (nonempty, nonwedge) directions (1 1 0) Mesh (nonempty) directions (1 1 0) All edges aligned with or perpendicular to nonempty directions. Boundary openness (8.47033e18 8.47033e18 4.51751e17) OK. Max cell openness = 1.35525e16 OK. Max aspect ratio = 2 OK. Minumum face area = 2.5e05. Maximum face area = 5e05. Face area magnitudes OK. Min volume = 2.5e07. Max volume = 2.5e07. Total volume = 0.0001. Cell volumes OK. Mesh nonorthogonality Max: 0 average: 0 Nonorthogonality check OK. Face pyramids OK. Max skewness = 1e08 OK. Mesh OK. > FOAM Warning : From function polyMesh::readUpdateState polyMesh::readUpdate() in file meshes/polyMesh/polyMeshIO.C at line 205 Number of patches has changed. This may have unexpected consequences. Proceed with care. Time = 0.00125 

November 9, 2009, 13:00 

#5  
Assistant Moderator
Bernhard Gschaider
Join Date: Mar 2009
Posts: 3,926
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Quote:
checkMesh assumes that the meshes at the different timesteps are from a moving mesh and should have the same set of patches. makeAxialMesh violates that assumption, but if you don't get any other complaints the mesh should be OK (move it to constant/polyMesh and try it) Bernhard 

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