mesh quality problems: maximum skewness larger than 0.98

cth_yao · January 26, 2012, 19:24

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!

-mAx- · January 27, 2012, 06:03

check your mesh quality, display worst elements, and fix problems.
You need to go back on your mesher for that

mali28 · January 27, 2012, 06:05

Quote:

Originally Posted by cth_yao

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.

shaoda169 · January 27, 2012, 06:50

Quote:

Originally Posted by -mAx-

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!

rgd · May 19, 2016, 11:59

Quote:

Originally Posted by mali28

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??

January 26, 2012, 19:24	mesh quality problems: maximum skewness larger than 0.98	#1
cth_yao New Member Join Date: Jan 2011 Posts: 10 Rep Power: 15	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 19:25. Reason: specify my question

January 27, 2012, 06:03		#2
-mAx- Super Moderator Maxime Perelli Join Date: Mar 2009 Location: Switzerland Posts: 3,297 Rep Power: 41	check your mesh quality, display worst elements, and fix problems. You need to go back on your mesher for that __________________ In memory of my friend Hervé: CFD engineer & freerider Last edited by -mAx-; January 27, 2012 at 06:22.

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