CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM Meshing & Mesh Conversion (https://www.cfd-online.com/Forums/openfoam-meshing/)
-   -   blockMesh problem (https://www.cfd-online.com/Forums/openfoam-meshing/112976-blockmesh-problem.html)

AbbasRahimi February 8, 2013 19:12

blockMesh problem
 
2 Attachment(s)
Hello,

Actually I built this mesh and blockMesh can successfully build a mesh out of it but when I look at the built mesh in OpenFoam it looks absolutely wrong on lower faces. Would you please give me some suggestion to resolve this problem. I have attached the generated Mesh and blockMeshDic to this email.

tnxs.
Abbas

Attachment 18894

Attachment 18896

kalle February 9, 2013 05:50

Hi,

a number of problems found: vertex 7 and 15 have the same coordinates. Block 2 and 3 have the wrong ordering. Shift place on the first four vertices with the last four. You can find such issues out with "paraFoam -block"

Good luck
Kalle

AbbasRahimi February 9, 2013 16:58

Quote:

Originally Posted by kalle (Post 406851)
Hi,

a number of problems found: vertex 7 and 15 have the same coordinates. Block 2 and 3 have the wrong ordering. Shift place on the first four vertices with the last four. You can find such issues out with "paraFoam -block"

Good luck
Kalle

Thank you Kalle.

Indeed your comment resolved the geometry problem. However when I check the mesh quality using checkMesh I get the following errors:

hecking geometry...
Overall domain bounding box (-0.05 -0.05 -0.005) (0.05 0.05 0.005)
Mesh (non-empty, non-wedge) directions (1 1 0)
Mesh (non-empty) directions (1 1 0)
All edges aligned with or perpendicular to non-empty directions.
***Boundary openness (0.094788 -1.15972e-18 4.46048e-18) possible hole in boundary description.
***Open cells found, max cell openness: 0.993196, number of open cells 40
<<Writing 40 non closed cells to set nonClosedCells
Minumum face area = 1.08126e-06. Maximum face area = 3.92598e-05. Face area magnitudes OK.
Min volume = 2e-300. Max volume = 8.62804e-08. Total volume = 3.91609e-05. Cell volumes OK.
#0 Foam::error::printStack(Foam::Ostream&) in "/opt/OpenFOAM-2.1.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/opt/OpenFOAM-2.1.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2
at sigaction.c:0
#3 acos in "/lib64/libm.so.6"
#4 Foam::primitiveMesh::checkFaceOrthogonality(bool, Foam::HashSet<int, Foam::Hash<int> >*) const in "/opt/OpenFOAM-2.1.1/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#5
in "/opt/OpenFOAM-2.1.1/platforms/linux64GccDPOpt/bin/checkMesh"
#6
in "/opt/OpenFOAM-2.1.1/platforms/linux64GccDPOpt/bin/checkMesh"
#7 __libc_start_main in "/lib64/libc.so.6"
#8
in "/opt/OpenFOAM-2.1.1/platforms/linux64GccDPOpt/bin/checkMesh"
Floating point exception (core dumped)

Would you please give me some hints how I can fix boundary openness?

Thank you.

kalle February 10, 2013 13:43

My guess is that the block's vertices ordering is still wrong, see the instructions on openfoam.org on how to place the vertices. If you do it the opposite way, you'll get such errors from checkMesh. blockMesh itself will not find out that the ordering is incorrect.

K


All times are GMT -4. The time now is 20:14.