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Old   July 5, 2006, 11:41
Default Negative Mesh Quality
  #1
hagupta
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I have made a hex mesh for my geometry. The pre-mesh quality(of the blocking) shows 0.3

However, after the mesh is loaded from the blocking, the quality is -0.15. How do I improve the quality?
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Old   July 5, 2006, 13:38
Default Re: Negative Mesh Quality
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Evan
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You probably have the surface quad mesh selected as well. If you unselect the surface in the parts list, only the quality of the volume elements will be calculated, and that should be the same as your premesh quality.
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Old   July 6, 2006, 05:48
Default Re: Negative Mesh Quality
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hagupta
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Dear Evan,

I checked it out. Even if I only select hexas in the list, the quality is 0. These elements between 0 & 0.05 (72 elements) are causing problems. I am also unable to load the mesh in CFX-Pre because of these bad elements.

If you dont mind, may I send you my block file ?

Thank You,

hagupta
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Old   July 6, 2006, 11:35
Default Re: Negative Mesh Quality
  #4
myron
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Another thing to check is that only the volume parts of interest are selected/active when you convert the Pre-Mesh to Unstructured Mesh.

You should also verify that there are no problems in the Pre-Mesh. When you look at the Pre-Mesh Quality (say the 2x2x2 determinant) set the min to -1 and the max to +1. You may actually have problems in the Pre-Mesh that weren't shown because of limits on the histogram. (It will also show the min and max in small letters in the histogram area itself.)
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