CFD Online Discussion Forums

CFD Online Discussion Forums (https://www.cfd-online.com/Forums/)
-   OpenFOAM Meshing & Mesh Conversion (https://www.cfd-online.com/Forums/openfoam-meshing/)
-   -   [blockMesh] Problem with meshing in openfoam (https://www.cfd-online.com/Forums/openfoam-meshing/220039-problem-meshing-openfoam.html)

Kevin Cao August 21, 2019 09:15

Problem with meshing in openfoam
 
Hello, I am a beginner in OpenFOAM. I want to simulate a jet ejected from a round nozzle into free space with o-h grid method.
The code of block is shown below:
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v1906 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}

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

scale 0.001;

vertices
(
(0 0 0) //0
(70 0 0) //1
(70 0 70)//2
(0 0 70)//3
(0 300 0)//4
(70 300 0)//5
(70 300 70)//6
(0 300 70)//7
//outside vertices
(42.071067812 0 27.92893219)//8
(27.92893219 0 27.92893219)//9
(27.92893219 0 42.071067812)//10
(42.071067812 0 42.071067812)//11
(42.071067812 300 27.92893219)//12 link 8
(27.92893219 300 27.92893219)//13 link 9
(27.92893219 300 42.071067812)//14 link 10
(42.071067812 300 42.071067812)//15 link 11
//vertices on the circle
(36.25 0 33.75)//16
(33.75 0 33.75)//17
(33.75 0 36.25)//18
(36.25 0 36.25)//19
(36.25 300 33.75)//20 link 16
(33.75 300 33.75)//21 link 17
(33.75 300 36.25)//22 link 18
(36.25 300 36.25)//23 link 19
//vertices in the circle(a square)
);

edges
(
arc 8 11 (35 0 30)
arc 11 10 (40 0 35)
arc 10 9 (35 0 40)
arc 9 8 (30 0 35)
arc 12 15 (35 300 30)
arc 15 14 (40 300 35)
arc 14 13 (35 300 40)
arc 13 12 (30 300 35)
);

blocks
(
hex (16 17 18 19 20 21 22 23) (10 10 10) simpleGrading (1 1 1)
hex (8 9 17 16 12 13 21 20) (10 100 10) simpleGrading (1 1 1)
hex (9 10 18 17 13 14 22 21) (10 100 10) simpleGrading (1 1 1)
hex (10 11 19 18 14 15 23 22) (10 100 10) simpleGrading (1 1 1)
hex (11 8 16 19 15 12 20 23) (10 100 10) simpleGrading (1 1 1)
hex (8 1 0 9 12 5 4 13) (10 100 10) simpleGrading (1 1 1)
hex (9 0 3 10 13 4 7 14) (10 100 10) simpleGrading (1 1 1)
hex (11 10 3 2 15 14 7 6) (10 100 10) simpleGrading (1 1 1)
hex (1 8 11 2 5 12 15 6) (10 100 10) simpleGrading (1 1 1)
);

boundary
(
inlet
{
type patch;
faces
(
(16 17 18 19)
(8 9 17 16)
(9 10 18 17)
(10 11 19 18)
(8 16 19 11)
);
}

outlet
{
type patch;
faces
(
(0 4 5 1)
(3 7 4 0)
(6 7 3 2)
(2 1 5 6)
(2 3 10 11)
(3 0 9 10)
(8 9 0 1)
(2 11 8 1)
(20 21 22 23)
(12 13 21 20)
(13 14 22 21)
(14 15 23 22)
(15 12 20 23)
(5 4 13 12)
(4 7 14 13)
(7 6 15 14)
(6 5 12 15)
);
}
)

mergePatchPairs
(
);


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

But the generation of mesh is failed. The result is shown below:
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // Create time Creating block mesh from "system/blockMeshDict" Creating block edges No non-planar block faces defined Creating topology blocks Creating topology patches Creating block mesh topology Check topology Basic statistics Number of internal faces : 16 Number of boundary faces : 22 Number of defined boundary faces : 22 Number of undefined boundary faces : 0 Checking patch -> block consistency Creating block offsets Creating merge list --> FOAM FATAL ERROR: Inconsistent number of faces between block pair 1 and 5 From function void Foam::blockMesh::calcMergeInfo() in file blockMesh/blockMeshMerge.C at line 223. FOAM exiting

It is appreciated it someone can help me.Thanks.

mwaqas August 22, 2019 04:44

Hello ziqu,
Here is your error message

Quote:

inconsistent number of faces between block pair 1 and 5
Quote:


blocks
(
hex (16 17 18 19 20 21 22 23) (10 10 10) simpleGrading (1 1 1)
hex (8 9 17 16 12 13 21 20) (10 100 10) simpleGrading (1 1 1) // Block 1
hex (9 10 18 17 13 14 22 21) (10 100 10) simpleGrading (1 1 1)
hex (10 11 19 18 14 15 23 22) (10 100 10) simpleGrading (1 1 1)
hex (11 8 16 19 15 12 20 23) (10 100 10) simpleGrading (1 1 1)
hex (8 1 0 9 12 5 4 13) (10 100 10) simpleGrading (1 1 1) // Block 5
hex (9 0 3 10 13 4 7 14) (10 100 10) simpleGrading (1 1 1)
hex (11 10 3 2 15 14 7 6) (10 100 10) simpleGrading (1 1 1)
hex (1 8 11 2 5 12 15 6) (10 100 10) simpleGrading (1 1 1)
);

Your these two blocks have different number of faces for common wall.
I have no idea, how your geometry look like. In short, the common patch/wall should have same number of faces.


Regards

Kevin Cao August 22, 2019 08:29

OK. I know where the problem is. The coordinate system is wrong so the index of vertices is totally wrong. Problem solved. anyway. Thanks.

UKARUN August 26, 2019 06:23

converting salome unv file to openfoam file
 
Dear All, I drew a T junction in Salome file and converted into a .unv file. later when I wanted to convert it into an openfoam file using the command ideasUnvToFoam filename.unv, I get an error message. I post the error message below. Can anyone help to solve this problem?

The error message is

/*---------------------------------------------------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v1812 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
Build : v1812 OPENFOAM=1812
Arch : "LSB;label=32;scalar=64"
Exec : ideasUnvToFoam Tjunction1.unv
Date : Aug 26 2019
Time : 15:20:10
Host : Arun
PID : 1102
I/O : uncollated
Case : /mnt/c/Users/Ebenezer/Downloads/OpenFOAM/OpenFOAM-v1812/tutorials/incompressible/simpleFoam/Tjunction2
nProcs : 1
trapFpe: Floating point exception trapping enabled (FOAM_SIGFPE).
fileModificationChecking : Monitoring run-time modified files using timeStampMaster (fileModificationSkew 10)
allowSystemOperations : Allowing user-supplied system call operations

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

Processing tag:164
Starting reading units at line 3.
l:1
units:" SI: Meter (newton)"
unitType:2
Unit factors:
Length scale : 1
Force scale : 1
Temperature scale : 1
Temperature offset : 273.15


Processing tag:2420
Skipping tag 2420 on line 9
Skipping section at line 9.

Processing tag:2411
Starting reading points at line 20.
Read 11776 points.

Processing tag:2412
Starting reading cells at line 23575.
First occurrence of element type 11 for cell 1 at line 23576
First occurrence of element type 44 for cell 361 at line 24656
First occurrence of element type 115 for cell 3511 at line 30956
Read 10125 cells and 3150 boundary faces.

Sorting boundary faces according to group (patch)

Constructing mesh with non-default patches of size:

--> FOAM Warning :
From function Foam::polyMesh::polyMesh(const Foam::IOobject&, Foam::pointField&&, const cellShapeList&, const faceListList&, const wordList&, const wordList&, const Foam::word&, const Foam::word&, const wordList&, bool)
in file meshes/polyMesh/polyMeshFromShapeMesh.C at line 590
Found 3150 undefined faces in mesh; adding to default patch.
End

mwaqas August 26, 2019 06:49

Hello Ukarun,


I am not sure about this problem. But from this message it is looking like that some of your boundary faces are undefined in your mesh.
Define every wall/face in your mesh and then try to convert it again.

Quote:

Found 3150 undefined faces in mesh; adding to default patch.

Regards

UKARUN August 28, 2019 02:47

Thank you so much

UKARUN August 28, 2019 02:50

Quote:

Originally Posted by UKARUN (Post 743260)
Thank you so much

Dear Waqas, Let me post the boundary conditions of my T junction channel. I have included all the walls, top, bottom, front and back under the category of Walls. I did not distinguish between them. My blockMeshDict file is

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v1812 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object blockMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //


scale 0.001;

vertices
(
(0 4 0) // 0
(0 3 0) // 1
(3 3 0) // 2
(3 0 0) // 3
(4 0 0) // 4
(4 3 0) // 5
(7 3 0) // 6
(7 4 0) // 7
(4 4 0) // 8
(3 4 0) // 9
(0 4 1) // 10
(0 3 1) // 11
(3 3 1) // 12
(3 0 1) // 13
(4 0 1) // 14
(4 3 1) // 15
(7 3 1) // 16
(7 4 1) // 17
(4 4 1) // 18
(3 4 1) // 19
);

blocks
(
hex (0 1 2 9 10 11 12 19) (10 30 10)
simpleGrading (1 1 1)
hex (9 2 5 8 19 12 15 18) (10 10 10)
simpleGrading (1 1 1)
hex (8 5 6 7 18 15 16 17) (10 30 10)
simpleGrading (1 1 1)
hex (2 3 4 5 12 13 14 15) (30 10 10)
simpleGrading (1 1 1)
);

edges
(
);

patches
(
patch inlet_one
(
(0 10 11 1)
)

patch inlet_two
(
(6 7 17 16)
)
patch outlet
(
(4 3 13 14)
)

);


wall Walls
(
(0 1 2 9)
(2 5 8 9)
(5 6 7 8)
(2 3 4 5)
(10 19 12 11)
(19 18 15 12)
(18 17 16 15)
(15 14 13 12)
(0 9 19 10)
(9 8 18 19)
(8 7 17 18)
(2 1 11 12)
(3 2 12 13)
(5 4 14 15)
(6 5 15 16)
)


mergePatchPairs
(
);

UKARUN August 28, 2019 02:53

My boundary condtions are
 
/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: v1812 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class polyBoundaryMesh;
location "constant/polyMesh";
object boundary;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

4
(
inlet_one
{
type patch;
nFaces 100;
startFace 27900;
}
inlet_two
{
type patch;
nFaces 100;
startFace 28000;
}
outlet
{
type patch;
nFaces 100;
startFace 28100;
}
defaultFaces
{
type empty;
inGroups 1(empty);
nFaces 3900;
startFace 28200;
}
)

UKARUN August 28, 2019 03:05

error in boundaryField
 
FoamFile
{
version 2.0;
format ascii;
class volVectorField;
object U;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions [0 1 -1 0 0 0 0];

internalField uniform (0 0 0);

boundaryField
{
inlet_one
{
type fixedValue;
value uniform (0.1 0 0);
}

inlet_two
{
type fixedvalue;
value uniform (-0.2 0 0);
}

outlet
{
type zeroGradient;
}

Walls
{
type fixedValue;
value uniform (0 0 0);
}


}

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

mwaqas August 28, 2019 03:15

What is the problem? I didn't get, what are you trying to ask


All times are GMT -4. The time now is 13:54.