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Problem with mesh. non closed cells.

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Old   April 2, 2013, 14:06
Smile Problem with mesh. non closed cells.
  #1
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Alexander
Join Date: Apr 2013
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AlexanderZ is on a distinguished road
I have a problem with my mesh. Please help me. What's wrong??
Here i attach some pictures to describe the problem.

Domain is a cylinder that consists of 5 hexa-blocks. Non closed cells appears on front and back surfaces of central block.

Here is blockMeshDict:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.0.1 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 2.53e-02;

vertices
(
(0 0.31496063 0) //0
(1.423423083 0.31496063 0) //1
(1.423423083 0.393700787 0) //2
(0 0.393700787 0) //3
(0 0.787401575 -0.472440945) //4
(1.423423083 0.787401575 -0.472440945) //5
(1.423423083 0.787401575 -0.393700787) //6
(0 0.787401575 -0.393700787) //7
(1.423423083 1.25984252 0) //8
(0 1.25984252 0) //9
(0 1.181102362 0) //10
(1.423423083 1.181102362 0) //11
(0 0.787401575 0.3937007) //12
(1.423423083 0.787401575 0.393700787) //13
(0 0.787401575 0.472440945) //14
(1.423423083 0.787401575 0.472440945) //15


);

blocks
(
hex (0 1 2 3 4 5 6 7)
(25 25 25)
simpleGrading (1.0 1.0 1.0)

hex (4 5 6 7 9 8 11 10)
(25 25 25)
simpleGrading (1.0 1.0 1.0)

hex (9 8 11 10 14 15 13 12)
(25 25 25)
simpleGrading (1.0 1.0 1.0)

hex (14 15 13 12 0 1 2 3)
(25 25 25)
simpleGrading (1.0 1.0 1.0)

hex (3 2 6 7 12 13 11 10)
(25 25 25)
simpleGrading (1.0 1.0 1.0)


);

edges
(
arc 0 4 (0 0.551181102 -0.40914586)
arc 1 5 (1.423423083 0.551181102 -0.40914586)
arc 4 9 (0 1.023622047 -0.40914586)
arc 5 8 (1.423423083 1.023622047 -0.40914586)
arc 9 14 (0 1.023622047 0.40914586)
arc 8 15 (1.423423083 1.023622047 0.40914586)
arc 14 0 (0 0.551181102 0.40914586952)
arc 15 1 (1.423423083 0.551181102 0.40914586952)

);

boundary
(


inlet
{
type patch;
faces
(
(0 4 7 3)
(4 9 10 7)
(9 14 12 10)
(14 0 3 12)
(3 7 10 12)


);
}

wall
{
type wall;
faces
(
(0 1 5 4)
(4 5 8 9 )
(9 8 15 14)
(14 15 1 0)

);
}



outlet
{
type patch;
faces
(
(1 5 6 2)
(5 8 11 6)
(8 15 13 11)
(15 1 2 13)
(2 6 11 13)

);
}

);

mergePatchPairs
(
);

// ************************************************** *********************** //

And checkMesh feedback:

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.0.1 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 2.0.1-51f1de99a4bc
Exec : checkMesh
Date : Apr 03 2013
Time : 00:42:07
Host : ************
PID : 3167
Case : ************
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: 82576
faces: 238750
internal faces: 230000
cells: 78125
boundary patches: 3
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 78125
prisms: 0
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 0

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
inlet 3125 3176 ok (non-closed singly connected)
wall 2500 2600 ok (non-closed singly connected)
outlet 3125 3176 ok (non-closed singly connected)

Checking geometry...
Overall domain bounding box (0 0.0079685 -0.0119528) (0.0360126 0.031874 0.0119528)
Mesh (non-empty, non-wedge) directions (1 1 1)
Mesh (non-empty) directions (1 1 1)
Boundary openness (1.2176e-08 -6.48171e-16 -1.31418e-16) OK.
***Open cells found, max cell openness: 1, number of open cells 2400
<<Writing 2400 non closed cells to set nonClosedCells
<<Writing 62500 cells with high aspect ratio to set highAspectRatioCells
Minumum face area = 3.81022e-08. Maximum face area = 1.08166e-06. Face area magnitudes OK.
Min volume = 2e-300. Max volume = 4.57339e-10. Total volume = 6.95536e-06. Cell volumes OK.
#0 Foam::error:rintStack(Foam::Ostream&) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#1 Foam::sigFpe::sigHandler(int) in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#2 in "/lib/libc.so.6"
#3 in "/lib/libm.so.6"
#4 acos in "/lib/libm.so.6"
#5 Foam:rimitiveMesh::checkFaceOrthogonality(bool, Foam::HashSet<int, Foam::Hash<int> >*) const in "/opt/openfoam201/platforms/linux64GccDPOpt/lib/libOpenFOAM.so"
#6
in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/checkMesh"
#7
in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/checkMesh"
#8 __libc_start_main in "/lib/libc.so.6"
#9
in "/opt/openfoam201/platforms/linux64GccDPOpt/bin/checkMesh"
Floating point exception



Thanks in advance!

Attached Images
File Type: jpg Screenshot-1.jpg (30.1 KB, 10 views)
File Type: jpg Screenshot-2.jpg (30.6 KB, 10 views)
File Type: jpg Screenshot-3.jpg (70.8 KB, 15 views)
File Type: jpg Screenshot-4.jpg (62.8 KB, 11 views)
File Type: jpg Screenshot-5.jpg (58.3 KB, 8 views)
AlexanderZ is offline   Reply With Quote

Old   April 3, 2013, 09:44
Default
  #2
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Alexander
Join Date: Apr 2013
Posts: 2
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AlexanderZ is on a distinguished road
Already solved this problem.

It turned out that the important role played by the ordering of the vertices of the blocks.
The first block is specified coordinate system grid: 0 1 is the X-axis, 1 2 is the Y-axis, and this axis is 0 4 is the Z-axis. All other units must be located in these coordinates as much as possible.

Sorry for my bad english .
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