[ce73stargazer]

Hi there

I used blockMesh to create a simple cube, with 2 cells defined in all x,y,z direction, however, when I used checkMesh, it shows this is a 2D mesh. I am not sure why, any suggestion?

This is the output from checkMesh

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | foam-extend: Open Source CFD |
| \\ / O peration | Version: 3.1 |
| \\ / A nd | Web: http://www.extend-project.de |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : 3.1-1dd681f6e943
Exec : checkMesh
Date : Jun 22 2016
Time : 09:13:05
Host : ubuntu14.04
PID : 5750
CtrlDict : /home/zhifang/foam/foam-extend-3.1/etc/controlDict
Case : /home/zhifang/OpenFoamTests/FoamExtendTests/damBreak
nProcs : 1
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).

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

Create polyMesh for time = 0

Time = 0

Mesh stats
all points: 27
live points: 27
all faces: 36
live faces: 36
internal faces: 12
cells: 8
boundary patches: 6
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 8
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 Area [m^2] Surface topology
inlet 4 9 4 ok (non-closed singly connected)
bottom 4 9 4 ok (non-closed singly connected)
outlet 4 9 4 ok (non-closed singly connected)
atmosphere 4 9 4 ok (non-closed singly connected)
front 4 9 4 ok (non-closed singly connected)
back 4 9 4 ok (non-closed singly connected)

Checking geometry...
This is a 2-D mesh
Overall domain bounding box (0 0 0) (2 2 2)
Mesh (non-empty, non-wedge) directions (1 1 0)
Mesh (non-empty) directions (1 1 0)
Mesh (non-empty, non-wedge) dimensions 2
All edges aligned with or perpendicular to non-empty directions.
Boundary openness (0 0 0) Threshold = 1e-06 OK.
Max cell openness = 0 OK.
Max aspect ratio = 1 OK.
Minumum face area = 1. Maximum face area = 1. Face area magnitudes OK.
Min volume = 1. Max volume = 1. Total volume = 8. Cell volumes OK.
Mesh non-orthogonality Max: 0 average: 0 Threshold = 70
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 2.5091e-15 OK.

Mesh OK.

End

And this is the blockMesh file

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.5 |
| \\ / A nd | Web: http://www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
( 0 0 0 ) //0
( 2 0 0 ) //1
( 0 2 0 ) //2
( 2 2 0 ) //3

( 0 0 2 ) //0
( 2 0 2 ) //1
( 0 2 2 ) //2
( 2 2 2 ) //3
);

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

edges
(
);

patches
(
patch inlet
(
(0 4 6 2)
)
wall bottom
(
(0 1 5 4)
)
patch outlet
(
(1 5 7 3)
)

patch atmosphere
(
(2 3 7 6)
)

empty front
(
(4 5 7 6)
)

empty back
(
(0 1 3 2)
)


);

mergePatchPairs
(
);

[Antimony]

Hi,

Your front and back patches have been defined as being of type empty.
As a result, OF considers it to be a 2D mesh...

Cheers,
Antimony