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-   -   How to use an ICEM wedge geometry? (http://www.cfd-online.com/Forums/openfoam/102096-how-use-icem-wedge-geometry.html)

galap May 22, 2012 07:05

How to use an ICEM wedge geometry?
 
1 Attachment(s)
Dear community,

I'm trying to get a simple wedge geometry running in OpenFOAM, which I created in ICEM. The wedge is a 10 deg slice with axis points (2 0 0) and (7 0 0). I ensured that the patch areas aren't aligned to coordinate planes. Front and back side are aligned to the yz plane. Symmetrie plane is aligned to yx plane (so both wedge patches are rotated by 5 deg). I attached an ICEM screenshot.
After importing in OpenFOAM by fluent3DMesh.. the boundary file looks like:

WEDGE1
{
type wedge;
nFaces 81;
startFace 819;
}
WEDGE2
{
type wedge;
nFaces 81;
startFace 900;
}
FRONT
{
type wall;
nFaces 36;
startFace 981;
}
BACK
{
type wall;
nFaces 36;
startFace 1017;
}
WALL
{
type wall;
nFaces 36;
startFace 1053;
}

Now, the probleme comes in when I checkMesh the case. The error is the, popular?, ***Number of edges not aligned with or perpendicular to non-empty directions: 5
<<Writing 10 points on non-aligned edges to set nonAlignedEdges



I absolutely have no clue what is the problem and how to fix this. I'm very grateful for your help. I'm looking forward to.

linnemann May 22, 2012 08:28

Hi

Page 18 of this report shows how to make a wedge geometry.

http://projekter.aau.dk/projekter/fi...784/Report.pdf

Keep in mind that a wedge case in OF does not handle flow normal to the wedge patch so you wont see swirl.

If you want to use your mesh directly and see swirl use cyclic with rotational offset BC's for the wedge patches.

galap May 22, 2012 09:07

Thanks, I'm going to check these things.

Tobi May 22, 2012 09:11

Quote:

Originally Posted by galap (Post 362412)
Dear community,

I'm trying to get a simple wedge geometry running in OpenFOAM, which I created in ICEM. The wedge is a 10 deg slice with axis points (2 0 0) and (7 0 0). I ensured that the patch areas aren't aligned to coordinate planes. Front and back side are aligned to the yz plane. Symmetrie plane is aligned to yx plane (so both wedge patches are rotated by 5 deg). I attached an ICEM screenshot.
After importing in OpenFOAM by fluent3DMesh.. the boundary file looks like:

WEDGE1
{
type wedge;
nFaces 81;
startFace 819;
}
WEDGE2
{
type wedge;
nFaces 81;
startFace 900;
}
FRONT
{
type wall;
nFaces 36;
startFace 981;
}
BACK
{
type wall;
nFaces 36;
startFace 1017;
}
WALL
{
type wall;
nFaces 36;
startFace 1053;
}

Now, the probleme comes in when I checkMesh the case. The error is the, popular?, ***Number of edges not aligned with or perpendicular to non-empty directions: 5
<<Writing 10 points on non-aligned edges to set nonAlignedEdges



I absolutely have no clue what is the problem and how to fix this. I'm very grateful for your help. I'm looking forward to.


Hi if you wanna use wedge you should have ONE CELL in the rotation direction.

Tobi

galap May 22, 2012 09:28

Yes indeed, the problem was the cell thickness. Ok, I don't want only one cell, so I'll try the cyclic boundaries..

VSass July 3, 2013 13:55

Quote:

Originally Posted by linnemann (Post 362436)
Hi

Page 18 of this report shows how to make a wedge geometry.

http://projekter.aau.dk/projekter/fi...784/Report.pdf

Keep in mind that a wedge case in OF does not handle flow normal to the wedge patch so you wont see swirl.

If you want to use your mesh directly and see swirl use cyclic with rotational offset BC's for the wedge patches.

Why is this happening? Is it because of the mesh been generated in Fluent or a feature of OF code?

bgane67 November 25, 2014 14:40

i want to design a nuzzle with cylinder to observe droplet's pinch off
i converted 2D to 3D with extrudeMeshDict
but after running setFields i recieved this error:
wedge front plane aligns with a coordinate plane.
The wedge plane should make a small angle (~2.5deg) with the coordinate plane
and the the pair of wedge planes should be symmetric about the coordinate plane.
Normal of face 0 is (0 0 -1) , implied coordinate plane direction is (0 0 -1)

From function wedgePolyPatch::initTransforms()
in file meshes/polyMesh/polyPatches/constraint/wedge/wedgePolyPatch.C at line 78.

my BlockMesh is:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

convertToMeters 0.001;


vertices
(
//back
(0 0 0)
(1 0 0)
(5 0 0)

(0 0.5 0)
(1 0.5 0)
(5 0.5 0)

(1 2 0)
(5 2 0)

//front
(0 0 0.1)
(1 0 0.1)
(5 0 0.1)

(0 0.5 0.1)
(1 0.5 0.1)
(5 0.5 0.1)

(1 2 0.1)
(5 2 0.1)

);

blocks
(
hex (0 1 4 3 8 9 12 11) (10 5 1) simpleGrading (1 1 1)
hex (1 2 5 4 9 10 13 12) (50 5 1) simpleGrading (1 1 1)
hex (4 5 7 6 12 13 15 14) (50 15 1) simpleGrading (1 1 1)

);

edges
(
);

boundary
(
inlet
{
type patch;
faces
(
(0 3 11 8)
);
}
outlet
{
type patch;
faces
(
(2 5 13 10)
(5 7 15 13)
(6 7 15 14)
);
}

fixedWall
{
type wall;
faces
(
(3 4 12 11)
(4 6 14 12)
);
}
axis
{
type patch;
faces
(
(0 1 9 8)
(1 2 10 9)
);
}

front
{
type patch;
faces
(
(0 1 4 3)
(1 2 5 4)
(4 5 7 6)
);
}
back
{
type patch;
faces
(
(8 9 12 11)
(9 10 13 12)
(12 13 15 14)
);
}
);

mergePatchPairs
(
);

// ************************************************** *********************** //
and my extrudemeshdict is:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object extrudeMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// What to extrude:
// patch : from patch of another case ('sourceCase')
// mesh : as above but with original case included
// surface : from externally read surface

constructFrom patch;
sourceCase "."; //the address of 2D geometry
sourcePatches (front);

// If construct from patch: patch to use for back (can be same as sourcePatch)
exposedPatchName back;

// Flip surface normals before usage. Valid only for extrude from surface or
// patch.
flipNormals true;

//- wedge extrusion in theta direction
extrudeModel wedge;
/*
6
(
linearDirection
linearNormal
linearRadial
radial
sigmaRadial
wedge
)
*/

nLayers 1;

expansionRatio 1.0;

wedgeCoeffs
{
axisPt (0 0 0); // point of axis
axis (1 0 0); // vector of axis
angle 5; // angle between front and back face
}

// Do front and back need to be merged? Usually only makes sense for 360
// degree wedges.
mergeFaces false;

// Merge small edges. Fraction of bounding box.
mergeTol 0.001;//1;


// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //
after creating mesh, i modified front and back patch boundary type from
patch to wedge in constant/polyMesh/bondary file



and my alpha.water is:

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.3.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class volScalarField;
object alpha.water;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 0 0 0 0 0 0];

internalField uniform 0;

boundaryField
{
inlet
{
type zeroGradient;
}

outlet
{
type zeroGradient;
}

fixedWall
{
type zeroGradient;
}

axis
{
type zeroGradient;
}

front
{
type wedge;
}
back
{
type wedge;
}
}

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




and my setFeildsDict is:



/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 2.2.0 |
| \\ / A nd | Web: www.OpenFOAM.org |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
location "system";
object setFieldsDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

defaultFieldValues
(
volScalarFieldValue alpha.water 0
);

regions
(
sphereToCell
{
centre (0 0 0);
radius 0.0005;
fieldValues
(
volScalarFieldValue alpha.water 1
);
}
);


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






thanks for your attention[/QUOTE]

tjliang January 18, 2015 11:10

Quote:

Originally Posted by Tobi (Post 362452)
Hi if you wanna use wedge you should have ONE CELL in the rotation direction.

Tobi

Hello Tobi, I have made almost the same geometry , when i export it from icem to fluent mesh , i just can't get the axis bounary in the mesh file. The axis is automatically neglected in the .msh file. Do you think i should change the axis boundary from edge to a very very narrow face(with only one cell broad). Axis is very important in openfoam especially when a wedge boundary appears.Thank you in advance.

Peng


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