[mn14cat]

Hi Philip,

I'm sorry for hijacking this post and I know this is in the completely wrong thread to ask this question, but I'm trying to create a wedge geometry as we had previously discussed in the thread.

I am trying to follow the guidance from the openFoam user guide:

https://www.openfoam.com/documentati...4.2-boundaries

https://www.openfoam.com/documentati...x13-480004.3.3

I have managed to create the geometry with blockMesh; however, when I run checkMesh I receive the following output:

[mn14cat@login2.arc4 nonLinBlock]$ checkMesh
/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | foam-extend: Open Source CFD |
| \\ / O peration | Version: 4.0 |
| \\ / A nd | Web: http://www.foam-extend.org |
| \\/ M anipulation | For copyright notice see file Copyright |
\*---------------------------------------------------------------------------*/
Build : 4.0
Exec : checkMesh -allGeometry -allTopology
Date : Jul 29 2022
Time : 11:18:48
Host : login2.arc4.leeds.ac.uk
PID : 241768
CtrlDict : "/home/home01/mn14cat/foam/mn14cat-4.0/run/usr_cases/solidMechanics/nonLinBlock/system/controlDict"
Case : /home/home01/mn14cat/foam/mn14cat-4.0/run/usr_cases/solidMechanics/nonLinBlock
nProcs : 1
SigFpe : Enabling floating point exception trapping (FOAM_SIGFPE).

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

Create polyMesh for time = 0

Time = 0

Mesh stats
all points: 6
live points: 6
all faces: 5
live faces: 5
internal faces: 0
cells: 1
boundary patches: 6
point zones: 0
face zones: 0
cell zones: 0

Overall number of cells of each type:
hexahedra: 0
prisms: 1
wedges: 0
pyramids: 0
tet wedges: 0
tetrahedra: 0
polyhedra: 0

Checking topology...
Boundary definition OK.
Point usage OK.
Upper triangular ordering OK.
Topological cell zip-up check OK.
Face vertices OK.
Face-face connectivity OK.
<<Writing 1 cells with with single non-boundary face to set oneInternalFaceCells
Number of regions: 1 (OK).

Checking patch topology for multiply connected surfaces ...
Patch Faces Points Area [m^2] Surface topology Bounding box
topLoading 1 3 0.05 ok (non-closed singly connected) (0 1 -0.05) (1 1 0.05)
axis 0 0 0 ok (empty) (0 0 0) (0 0 0)
freeSurface 1 4 0.1 ok (non-closed singly connected) (1 0 -0.05) (1 1 0.05)
fixedBottom 1 3 0.05 ok (non-closed singly connected) (0 0 -0.05) (1 0 0.05)
back 1 4 1.00125 ok (non-closed singly connected) (0 0 -0.05) (1 1 0)
front 1 4 1.00125 ok (non-closed singly connected) (0 0 0) (1 1 0.05)

Checking geometry...
This is a 3-D mesh
Overall domain bounding box (0 0 -0.05) (1 1 0.05)
Mesh (non-empty, non-wedge) directions (1 1 0)
Mesh (non-empty) directions (1 1 1)
Mesh (non-empty, non-wedge) dimensions 2
***Number of edges not aligned with or perpendicular to non-empty directions: 4
Writing 6 points on non-aligned edges to set nonAlignedEdges
Boundary openness (0 0 0) Threshold = 1e-06 OK.
Max cell openness = 0 OK.
Max aspect ratio = 20 OK.
Minumum face area = 0.05. Maximum face area = 1.00125. Face area magnitudes OK.
Min volume = 0.05. Max volume = 0.05. Total volume = 0.05. Cell volumes OK.
Non-orthogonality check OK.
Face pyramids OK.
Max skewness = 0.330008 OK.
Min/max edge length = 0.1 1.00125 OK.
All angles in faces OK.
Face flatness (1 = flat, 0 = butterfly) : average = 1 min = 1
All face flatness OK.
***Cells with small determinant found, number of cells: 1
Writing 1 under-determined cells to set underdeterminedCells

Failed 2 mesh checks.

End

I have tried to read up on the cause of the non-aligned edges on a couple of threads on the forum

https://www.cfd-online.com/Forums/op...ion-print.html

Number of edges not aligned with or perpendicular to non-empty directions

but I still don't understand the cause of the problem.

This is my blockMeshDict file:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | foam-extend: Open Source CFD |
| \\ / O peration | Version: 4.0 |
| \\ / A nd | Web: http://www.foam-extend.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "constant/polyMesh";
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 1;

vertices
(
(0 0 0) //0
(1 0 -0.05) //1
(1 1 -0.05) //2
(0 1 0) //3
(1 0 0.05) //4
(1 1 0.05) //5
// (1 1 0.05) //6
// (0 1 0.05) //7
);

blocks
(
hex ( 0 3 3 0 1 2 5 4 ) (10 10 1) simpleGrading (1 1 1)
);

edges
(
);

patches
(
patch topLoading
(
(2 3 3 5)
)

symmetry axis
(
(3 0 0 3)
)

patch freeSurface
(
(1 2 5 4)
)

patch fixedBottom
(
(0 1 4 0)
)

wedge back
(
(0 1 2 3)
)

wedge front
(
(3 5 4 0)
)
);

mergePatchPairs
(
);


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

I would really appreciate any guidance on the root of this problem.

p.s. I also tried to visualise the problem in paraview but that also didnt help at all.

Many Thanks in advance

Craig

[bigphil]

Hi Craig,

Have a look at the following axisymmetric blockMeshDict example from solids4foam: https://bitbucket.org/philip_cardiff...uniaxialRod.m4