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[GAMBIT] mesh skewness

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Old   March 4, 2012, 00:21
Default mesh skewness
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I am running a 2D gas-solid fluidized bed reactor simulation in fluent. The grid was created in gambit. my simulation breaks down after some time with the message divergence detected in AMG solver. I have searched many forums and people recommend that i check the quality of the mesh. Having done so the min and max skewness of my mesh is 1.305729e-10. can somebody advice me if this is good enough! what is the criteria for mesh skewness
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Old   March 5, 2012, 02:38
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Having done so the min and max skewness of my mesh is 1.305729e-10.

do it once again: in Gambit go in examine mesh and click on "worst element". And check the value of the skewness.
http://my.fit.edu/itresources/manual...equiangle_skew
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Old   March 7, 2012, 07:27
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Thank you max! I checked it and it is 0.1306 i.e in the range between 0 and 2.5 meaning it is excellent but I can not still understand why i am getting the reverse flow problem. I have reduced my under relaxation factors as well!
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Old   March 7, 2012, 09:52
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reverse flow may occures at the start of computation, but should disappear (no link with skewness).
else you may extend your outlet domain, it is closed to an obstacle
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Old   June 7, 2012, 08:21
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Hi...
I am a beginner in ANSYS FLUENT 13.0, so please excuse me to answer this simple question
" how to check the skew ness and other parameters(other than sizing,inflation,statitics etc which are visible when mesh is highlighted) of the mesh?

Thank you in advance...
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Old   June 7, 2012, 09:32
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In Ansys Meshing after you generate mesh in the Details choose 'Statistics' (click the + icon to unfold it). There you can see number of elements and nodes. And in the 'Mesh Metric' you can choose different kinds of mesh properties including Skewness and Orthogonal Quality.

In FLUENT when the mesh is loaded you can click 'Check' in the General tab and 'Report Quality' to check the orthogonal quality and aspect ratio properties.



Sizing and inflation options are also visible in the 'Details of Mesh' when you simply click 'Mesh' in the Outline tree in Ansys Meshing. If you have any locally applied inflation, then it appears under 'Mesh' in the outline tree, and after clicking desired inflation there you will also see its properties in the 'Details'.
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Old   June 7, 2012, 10:56
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In Ansys Meshing after you generate mesh in the Details choose 'Statistics' (click the + icon to unfold it). There you can see number of elements and nodes. And in the 'Mesh Metric' you can choose different kinds of mesh properties including Skewness and Orthogonal Quality.

In FLUENT when the mesh is loaded you can click 'Check' in the General tab and 'Report Quality' to check the orthogonal quality and aspect ratio properties.



Sizing and inflation options are also visible in the 'Details of Mesh' when you simply click 'Mesh' in the Outline tree in Ansys Meshing. If you have any locally applied inflation, then it appears under 'Mesh' in the outline tree, and after clicking desired inflation there you will also see its properties in the 'Details'.
Thanks everdimension for your detailed reply.....it helped me a lot....
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Old   July 21, 2012, 14:03
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Quote:
Originally Posted by -mAx- View Post

do it once again: in Gambit go in examine mesh and click on "worst element". And check the value of the skewness.
http://my.fit.edu/itresources/manual...equiangle_skew

How do we remove these worst element??(ANSYS V14)
I find some highly skewed cells near some simple surfaces(maximum skewness :0.999999)

suggestions will be helpfull..
.
Thanks in advance
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