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Trimmed Mesh Cell Quality

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Old   August 13, 2018, 11:15
Default Trimmed Mesh Cell Quality
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Good Morning,

How come if you have a perfect cube and you use a trimmed mesh, you will never have all the cells at 100 % quality?

Thank you!
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Old   August 13, 2018, 19:55
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You can certainly mesh a perfect (or very, very closer to it) cube with the trimmer. But you need your cube to align perfectly with the octree mesh.

The trimmer autogenerates a background mesh over objects and then 'trims' out the cells that are not in desired volumes. If the desired volume is perfectly aligned with the background mesh, then you get nearly exactly the perfect background mesh.
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Old   September 14, 2018, 13:10
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Thank you, how do I perfectly align the desired volume with the background mesh then?
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Old   September 17, 2018, 11:16
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I believe that would be a structured mesh and you cannot do that with star-ccm, currently. You would have to mesh using a 3rd party software and import that.

I could be wrong.
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Old   September 17, 2018, 12:30
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You can use "Perform Mesh Alignment" in the trimmer to accomplish what you are describing. The wrapper has this same functionality.

You can use that alignment point as an anchor for the bounding box of the geometry. Look at the documentation for more information.
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Old   September 17, 2018, 23:28
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Quote:
Originally Posted by SoAero View Post
You can use "Perform Mesh Alignment" in the trimmer to accomplish what you are describing. The wrapper has this same functionality.

You can use that alignment point as an anchor for the bounding box of the geometry. Look at the documentation for more information.

This will allow you to align the mesh at a particular point, but IMO a superior method is to have the trimmer use a particular coordinate system. You can define a coordinate system under the trimmer mesher object in an operation or continuum. The coordinate system approach allows the background mesh to have any orientation and position.


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Originally Posted by fluid23 View Post
I believe that would be a structured mesh and you cannot do that with star-ccm, currently. You would have to mesh using a 3rd party software and import that.

I could be wrong.

STAR-CCM+ can make structured meshes via the Directed Mesher. The solver will still treat them as unstructured. They'll have great quality though.
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