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Checkmesh shows fault in snappyhexmeshed pipe

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Old   July 12, 2012, 07:29
Default Checkmesh shows fault in snappyhexmeshed pipe
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Senol
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Hi dear foamers;

I made a pipe in Solidworks and built mesh with snappyhexmesh. It has three parts inlet outler and cylinder, i am studying on internal flow. I tried to solve with icoFoam but courant number gets higher step by step, so i used checkmesh. I guess the problem is about mesh, because when i run checkmesh it says "Failed 1 mesh checks". Can somebody help me if this following file shows that the problem is about the mesh and how can i solve it. Also if there is a problem in mesh which line shows the problem.

thanks all.

Senol.





/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.1.1 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 2.1.1-221db2718bbb
Exec : checkMesh
Date : Jul 12 2012
Time : 14:05:22
Host : "ubuntu"
PID : 10203
Case : /home/akkus/OpenFOAM/akkus-2.1.1/run/tutorials/mesh/snappyHexMesh/cylinder
nProcs : 1
sigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster
allowSystemOperations : Disallowing user-supplied system call operations

// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
Create time

Create polyMesh for time = 0

Time = 0

Mesh stats
points: 188693
faces: 478963
internal faces: 431013
cells: 145288
boundary patches: 4
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 120193
prisms: 9693
wedges: 0
pyramids: 0
tet wedges: 86
tetrahedra: 0
polyhedra: 15316

Checking topology...
Boundary definition OK.
Cell to face addressing 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
allBoundary 0 0 ok (empty)
montajSilindir_Montaj1-silindir-128917 29573 ok (non-closed singly connected)
montajİnlet_Montaj1-inlet-19572 9808 ok (non-closed singly connected)
montajOutlet_Montaj1-outlet-19461 9695 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (0.0050909 0.00519532 0.0001005) (0.0250449 0.0251742 0.100101)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (-1.18841e-15 9.16711e-16 1.90025e-16) OK.
Max cell openness = 3.37214e-16 OK.
Max aspect ratio = 30.2737 OK.
Minumum face area = 1.03897e-08. Maximum face area = 5.15382e-06. Face area magnitudes OK.
Min volume = 3.6838e-12. Max volume = 2.57697e-09. Total volume = 3.12138e-05. Cell volumes OK.
Mesh non-orthogonality Max: 74.8039 average: 19.8508
*Number of severely non-orthogonal faces: 13552.
Non-orthogonality check OK.
<<Writing 13552 non-orthogonal faces to set nonOrthoFaces
Face pyramids OK.
***Max skewness = 7.91641, 10 highly skew faces detected which may impair the quality of the results
<<Writing 10 skew faces to set skewFaces
Coupled point location match (average 0) OK.

Failed 1 mesh checks.

End
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Old   July 12, 2012, 11:12
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Eysteinn Helgason
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There are multiple things that can be wrong in the meshing process.

Here is some discussion on a pipe mesh and there is also a snappyHexMesh file there that you could take a look at and compare.

You mention that your mesh is made up of 3 parts, inlet, outlet and cylinder. According to checkMesh there seem to be 4 boundary patches though. Maybe something you can check out in constant/polymesh/boundary.

Hope this helps!
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Old   July 13, 2012, 14:12
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Senol
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hi eynsteinn

I figured out that i designed blockmeshdict wrong, i redisigned and now everything is ok



Quote:
Originally Posted by eysteinn View Post

You mention that your mesh is made up of 3 parts, inlet, outlet and cylinder. According to checkMesh there seem to be 4 boundary patches though. Maybe something you can check out in constant/polymesh/boundary.
The pipe has three parts but to use snappyhexmesh (as i know) blockmesh must be build. 4th part belongs blockmesh.

Thanks for your interest.
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