[Gosaburo]

Hello everybody,

I've read many threads of this forum over the last year and most of the time was able to find the error by myself. Now comes the time that I need to open a post :-)

First of all, I would like to thank the community for your kind help, as far as I've seen it, you are always kind and try to help everybody as good as you can.

So, now to my problem:

I'm trying to simulate an internal flow and prepared the STL file with all its regions. But when it comes to the meshing process in CfMesh, some edges are not meshed correctly. I've looked at the .vtk file, which shows the edges generated by the command "SurfaceFeatureEdges -angle 30". It seems to detect the edges correctly, but didn't place the mesh nodes on these edges.

My mesh has some very high skewness values of about 400-1200 which are way too high.

I've played a bit with the cellsize, but that did not help me out a lot (I did not cut the cell size by half because this would increase the data space too much)

Thank you in advance :-)

/*--------------------------------*- C++ -*----------------------------------*\
| =========                 |                                                |
| \\      /  F ield         | cfMesh: A library for mesh generation          | 
|  \\    /   O peration     |                                                |
|   \\  /    A nd           | Author: Franjo Juretic                         | 
|    \\/     M anipulation  | E-mail: franjo.juretic@c-fields.com            |
\*---------------------------------------------------------------------------*/

FoamFile
{
    version   2.0;
    format    ascii;
    class     dictionary;
    location  "system";
    object    meshDict;
}

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

surfaceFile "edges.fms";

maxCellSize 0.001;    

surfaceMeshRefinement
{
  wall
    {
    surfaceFile "CAD/STL/wall.stl";
    additionalRefinementLevels 3;
    refinementThickness 0.00004;
    }
} 

boundaryLayers
{
//    nLayers 3;

//    thicknessRatio 1.2;

//    maxFirstLayerThickness 0.5;

    patchBoundaryLayers
    {
        "wall.*"
        {
            nLayers           3;

            thicknessRatio    1.2;

            maxFirstLayerThickness 0.00001;

            allowDiscontinuity 0;
        }       
    }
}


renameBoundary
{
    newPatchNames
    {
    wall
      {
      newName walls;
      type    wall;
      }
      
     leftWall1
      {
      newName cyclic1;
      type    cyclicAMI;
      neighbourPatch  cyclic0;
      transform rotational;
      rotationAxis    (0 0 1);
      rotationCentre  (0 0 0);
      rotationAngle   180;          // degrees     
      }
          
      leftWall2
      {
      newName cyclic1;
      type    cyclicAMI;
      neighbourPatch  cyclic0;
      transform rotational;
      rotationAxis    (0 0 1);
      rotationCentre  (0 0 0);
      rotationAngle   180;          // degrees     
      }
      
     rightWall1
      {
      newName cyclic0;
      type    cyclicAMI;
      neighbourPatch  cyclic1;
      transform rotational;
      rotationAxis    (0 0 1);
      rotationCentre  (0 0 0);
      rotationAngle   180;          // degrees     
      } 
      
      rightWall2
      {
      newName cyclic0;
      type    cyclicAMI;
      neighbourPatch  cyclic1;
      transform rotational;
      rotationAxis    (0 0 1);
      rotationCentre  (0 0 0);
      rotationAngle   180;          // degrees     
      }  
       
      inlet
      {
      newName inlet;
      type    patch;
      } 
         
      outlet
      {
      newName outlet;
      type    patch;
      }    
    
    }
    


}
// ************************************************************************* //

[student666]

Hi,

First, are you sure of the command line you're typing? I generally use:

surfaceFeatureEdges.exe surfacefile.stl surfacefile.fms -angle 30

and have a check with paraview that all feature Edges have been captured:

FMSToSurface -exportFeatureEdges surfacefile.fms temp.fms

I think you have also two more options to capture the edges properly:

1. separate each surface containing the edges and define them as separate files.
2. define locally a edgeMeshRefinement phase

point 1 enforce cfMesh to capture properly edges.
e.g.

maxCellSize 0.008;
//boundaryCellSize 0.001375;
localRefinement
	{
		ext1					{cellSize 0.004;}
		interAirAmbAirComb1		{cellSize 0.0025;}
		interAirAmbAirComb2		{cellSize 0.0025;}
		interAirAmbGlass		{cellSize 0.004;}
		interAirAmbSolido1		{cellSize 0.003;} //0.0025 //totale
		interAirAmbSolido2		{cellSize 0.00075;} //0.0025
		interAirAmbSolido3		{cellSize 0.00075;} //0.0025
		interAirAmbSolido4		{cellSize 0.002;} //0.0025 
		interAirAmbSolido5		{cellSize 0.002;}
		interAirAmbSolido6		{cellSize 0.002;} 		
		outletComfort			{cellSize 0.003;}
		//ext 2/3/4/3/5 - symmetryAmb - wallSerbatoio
	}
surfaceMeshRefinement
	{
		refVentilatore	{surfaceFile  "refineGeometry/refVentilatore.stl";	additionalRefinementLevels 4;} // refinementThickness 0.002; }
	}
edgeMeshRefinement
	{
		asole						{edgeFile "refineGeometry/asole.vtk";additionalRefinementLevels 4;} //refinementThickness 0.002;
		angolo2						{edgeFile "refineGeometry/angolo2.vtk";additionalRefinementLevels 6;}

	}