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-   -   Mesh check fail (http://www.cfd-online.com/Forums/openfoam/90472-mesh-check-fail.html)

eddiejohn July 11, 2011 11:28

Mesh check fail
 
Hi all,

Currently running trials for solidworks -> pointwise -> openfoam -> paraview process of simulations. I have created my model in solidworks, then created a hybrid mesh with openfoam boundaries in pointwise. When i import and execute checkMesh in terminal i get the following...

***Boundary openness (-1.25496e-08 0.00676147 1.33344e-05) possible hole in boundary description.
***Open cells found, max cell openness: 1, number of open cells 69988
<<Writing 69988 non closed cells to set nonClosedCells

Failed 2 mesh checks.

Anyone elese had similar issues or used the same program processes that i am trying to achieve? Any help would be welcomed.

Regards

John

cnsidero July 11, 2011 14:25

eddiejohn,

What version of Pointwise are you using (Help > About Pointwise)? There was a problem with the orientation of prism blocks getting reversed when exported to OpenFOAM - and thus causing the error you're seeing - but that was fixed relatively recently.

If possible, it would also be helpful to see an image of what your mesh (in Pointwise) looks like.

-Chris

eddiejohn July 13, 2011 05:02

1 Attachment(s)
Chris,

Thankyou for your reply. I am running the following version;
Pointwise V16.04 Release 3 -- Optimized Build 0138141200 Windows 64-bit. Its a 30 day trial.


Please find attatched a jpeg of the mesh in pointwise. Tried just ignoring the error and running OpenFoam but to no avail. Any ideas?



Thanks


John

cnsidero July 13, 2011 14:28

Who are you currently evaluating for/with? Your mesh looks fine in the picture but you might have to send it to me to look at it closer. Let me know if you are able to - send me an email.

Rophys July 20, 2011 10:01

checkMesh fail
 
hello everybody,

I'm using the rhoCentral Foam (2.0 version) and I have been problems to generate my mesh. My mesh is composed by two regions, the first one is rectangular and the second one is a parallelepiped. For the region when I run the commands blockMesh and checkMesh everything is ok, but when I introduce the second region the openFoam give the following error: "number of edges not aligned or perpendicular to non-empty directions". I substituted the parallelepiped region for other rectangular region and everything works fine. Maybe the openFoam don't accept angles in the mesh ? Somebody could help me ? Thanks

wouter July 21, 2011 17:00

Quote:

Originally Posted by eddiejohn (Post 315946)
Chris,

Thankyou for your reply. I am running the following version;
Pointwise V16.04 Release 3 -- Optimized Build 0138141200 Windows 64-bit. Its a 30 day trial.


Please find attatched a jpeg of the mesh in pointwise. Tried just ignoring the error and running OpenFoam but to no avail. Any ideas?



Thanks


John

hello John,

Maybe you are allready aware of this, so maybe an irrelevant answer.
As far as I know solid works draws the hardware (pipe wall), where openfoam needs a mesh of the fluid (inside of pipe). so you need to subtract the hardware from the enclosing fluid and mesh this.

hope this helps
Wouter

OF_NACA July 22, 2011 06:06

mesh issue
 
Hi foamers !

I've an issue with my mesh generated with blockMesh and snappyHexMesh (OpenFoam V1.7) with a geometry given by a .obj file. I work in 2D, but the mesh present some errors and I can't find why ! Can sb help me ??
I think that errors come from some edges that pass through several cells and even through the foil !
I put a picture of my mesh and my snappyHexMeshDict file down below !
Thanks in advance!

/*--------------------------------*- C++ -*----------------------------------*\
| ========= | |
| \\ / F ield | OpenFOAM: The Open Source CFD Toolbox |
| \\ / O peration | Version: 1.7.1 |
| \\ / A nd | Web: www.OpenFOAM.com |
| \\/ M anipulation | |
\*---------------------------------------------------------------------------*/
FoamFile
{
version 2.0;
format ascii;
class dictionary;
object snappyHexMeshDict;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

// Which of the steps to run
castellatedMesh true;
snap true;
addLayers true;


geometry
{
wing_NACA66.obj
{
type triSurfaceMesh;
}

refinementBox
{
type searchableBox;
min (-0.5 -0.5 -1);
max ( 2 0.5 1);
}
};



// Settings for the castellatedMesh generation.
castellatedMeshControls
{

maxLocalCells 1000000;


maxGlobalCells 2000000;

minimumRefine

minRefinementCells 100;

nCellsBetweenLevels 6;





features ();




refinementSurfaces
{
wing_NACA66.obj
{

level (4 4);
}
}


resolveFeatureAngle 30;



refinementRegions
{
//refinementBox
//{
// mode inside;
// levels ((1e15 3));
//}
wing_NACA66.obj
{
mode distance;
levels ((0.15 4) (0.3 3) (0.4 2));
}
}



locationInMesh (-0.5 0 0);


allowFreeStandingZoneFaces true;
}



snapControls
{

nSmoothPatch 3;


tolerance 4.0;


nSolveIter 30;

nRelaxIter 5;
}




addLayersControls
{

relativeSizes false;

layers
{
"wing.*"
{
nSurfaceLayers 3;
}
}

expansionRatio 1.2;

finalLayerThickness 0.002;

minThickness 0.0002;

nGrow 0;


// Advanced settings


featureAngle 60;

nRelaxIter 5;

nSmoothSurfaceNormals 1;


nSmoothNormals 3;


nSmoothThickness 10;

maxFaceThicknessRatio 0.5;


maxThicknessToMedialRatio 0.3;


minMedianAxisAngle 90;


nBufferCellsNoExtrude 0;



nLayerIter 50;
}




meshQualityControls
{

maxNonOrtho 65;


maxBoundarySkewness 20;
maxInternalSkewness 4;

maxConcave 80;

minVol 1e-13;

minTetVol 1e-20;


minArea -1;


minTwist 0.05;

//- minimum normalised cell determinant

minDeterminant 0.001;


minFaceWeight 0.05;


minVolRatio 0.01;


minTriangleTwist -1;

nSmoothScale 4;

errorReduction 0.75;
}



debug 0;


mergeTolerance 1E-6;


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

[IMG]file:///mnt/home/stagiaires/marie-alix.lorin/Desktop/Capture.png[/IMG]

OF_NACA July 22, 2011 06:07

1 Attachment(s)
and the picture !


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