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mesh quality problems: maximum skewness larger than 0.98

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Old   January 26, 2012, 18:24
Default mesh quality problems: maximum skewness larger than 0.98
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Hi there. I am simulating a numerical wave tank with a chamber in it. I build the mesh with DM meshing, but when I run it in FLUENT, there is a warning

maximum cell skewness exceed 0.98

what is the problem that causes the warning?

besides this warning, there are two other things, the maximum cell squish is 0.9655 and the maximum aspect ratio is 256.198
does it mean the mesh quality is low?

how can I deal with these problems?

thanks!

Last edited by cth_yao; January 26, 2012 at 18:25. Reason: specify my question
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Old   January 27, 2012, 05:03
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check your mesh quality, display worst elements, and fix problems.
You need to go back on your mesher for that
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Old   January 27, 2012, 05:05
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Quote:
Originally Posted by cth_yao View Post
Hi there. I am simulating a numerical wave tank with a chamber in it. I build the mesh with DM meshing, but when I run it in FLUENT, there is a warning

maximum cell skewness exceed 0.98

what is the problem that causes the warning?

besides this warning, there are two other things, the maximum cell squish is 0.9655 and the maximum aspect ratio is 256.198
does it mean the mesh quality is low?

how can I deal with these problems?

thanks!

Mesh skewness is high if you are using unstructured mesh. But generally, it should be less than 0.85 for tetrahedral cells.
Even a few cells with high skewness can cause trouble in convergence and may even lead to divergence.
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Old   January 27, 2012, 05:50
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Originally Posted by -mAx- View Post
check your mesh quality, display worst elements, and fix problems.
You need to go back on your mesher for that
Yes, you r right. Actually it is very important to pay efforts to generate 'good' mesh before iteration in FLUENT!
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Old   May 19, 2016, 10:59
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Quote:
Originally Posted by mali28 View Post
Mesh skewness is high if you are using unstructured mesh. But generally, it should be less than 0.85 for tetrahedral cells.
Even a few cells with high skewness can cause trouble in convergence and may even lead to divergence.
Do you have the rule of thumb for maximum skewness for all types of mesh??
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