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snappyHexMesh - Poor surface

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Old   August 12, 2011, 06:08
Default snappyHexMesh - Poor surface
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Daniel
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I'm trying to mesh an axisymmetric slender body (a finless missile) using snappyHexMesh. I have a very high quality .stl file and have modified the motorBike snappyHexMeshDict rather than write from scratch as I'm just getting to grips with openFoam. However, when I run sHM I get a very low quality surface as can be seen in the attached image for the first and second 'timestep' during sHM.

What I would like to know is which parameter in which Dict is it that controls the quality of the surface matching? I would be inclined to say that increasing the grid resolution in blockMeshDict would help. If this is so, is it possible to create a blockMesh cuboid around the missile geometry of high resolution which is contained within a larger domain cuboid? (See attached image)
Attached Images
File Type: png Domain_new.png (8.1 KB, 64 views)
File Type: png sHM.png (14.2 KB, 69 views)
Attached Files
File Type: txt blockMeshDict.txt (1.6 KB, 10 views)
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Old   August 12, 2011, 07:20
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Daniel
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OK, so it looks like I hadn't told sHMDict to refine the surface, only the refinement area.

Before I had:
Code:
 refinementRegions
    {
        refinementBox
        {
            mode inside;
	 levels ((0.5 1));
        }

    }
But now I have
Code:
 refinementRegions
    {
        refinementBox
        {
            mode inside;
	 levels ((0.5 1));
        }
motorBike
      {   mode distance;  
          levels ((0.0001 6) (0.001 5) (0.01 4) (0.1 3) (0.2 2));
      } 
    }
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Old   March 16, 2014, 12:43
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Sasan Ghomi
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Hi Daniel ,Have you solved the problem? Have you gotten a high quality surface? Actually I have a problem similar to you!!

Best regards,
Sasan.
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