CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > OpenFOAM Meshing & Mesh Conversion

blockMesh problem

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Display Modes
Old   February 8, 2013, 19:12
Default blockMesh problem
  #1
New Member
 
Abbas Rahimi
Join Date: Jan 2013
Posts: 20
Rep Power: 4
AbbasRahimi is on a distinguished road
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

Cylinder.jpg

cylinder.txt
AbbasRahimi is offline   Reply With Quote

Old   February 9, 2013, 05:50
Default
  #2
Senior Member
 
Karl-Johan Nogenmyr
Join Date: Mar 2009
Location: Linköping
Posts: 256
Rep Power: 12
kalle is on a distinguished road
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
kalle is offline   Reply With Quote

Old   February 9, 2013, 16:58
Default
  #3
New Member
 
Abbas Rahimi
Join Date: Jan 2013
Posts: 20
Rep Power: 4
AbbasRahimi is on a distinguished road
Quote:
Originally Posted by kalle View Post
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:rintStack(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:rimitiveMesh::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.
AbbasRahimi is offline   Reply With Quote

Old   February 10, 2013, 13:43
Default
  #4
Senior Member
 
Karl-Johan Nogenmyr
Join Date: Mar 2009
Location: Linköping
Posts: 256
Rep Power: 12
kalle is on a distinguished road
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
kalle is offline   Reply With Quote

Reply

Tags
blockmesh, wrong mesh

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are On
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
UDF compiling problem Wouter Fluent UDF and Scheme Programming 6 June 6, 2012 04:43
Can I solve this problem by Fluent? Kai_kc FLUENT 1 October 27, 2010 05:29
natural convection problem for a CHT problem Se-Hee CFX 2 June 10, 2007 06:29
Adiabatic and Rotating wall (Convection problem) ParodDav CFX 5 April 29, 2007 19:13
Is this problem well posed? Thomas P. Abraham Main CFD Forum 5 September 8, 1999 14:52


All times are GMT -4. The time now is 21:55.