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I got a problem after I repaired and improved the quality of mesh in FLUENT

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Old   June 8, 2013, 23:22
Default I got a problem after I repaired and improved the quality of mesh in FLUENT
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Loi Pham
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Dear all,

I am using the realizable k-epsilon turbulence model in FLUENT to simulate the wind flow in the atmosphere through UDFs. Before I ran simulation, I had used "mesh/repair-improve/improve-quality". However I had an error message " Error: Divergence detected in AMG solver: epsilon
Error Object: #f "
Does anybody know how to solve it? Please tell me. Thank you.
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File Type: jpg Problem with mew mesh.jpg (93.4 KB, 41 views)
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Old   June 8, 2013, 23:57
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sina
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Dear Loi
Mesh repair in fluent is not good. you can use CFX for mesh adaption. its clear that a region in your domain has bad quality becuase after time elpasing when flow recive to specific region solver had been diverged.

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Old   June 9, 2013, 00:07
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Dear Sina,

I am using FLuent. I did not try to use CFX yet. For repairing and adapting the quality of mesh in FLUENT, should we do that? Because I just start use CFD so I have rare experience. Please tell me. thank you.
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Old   June 9, 2013, 00:12
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Why you want repair your mesh? Do you have any problem with your mesh? plz click on MESH on fluent toolbar then click on check mesh and send result for me.
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Old   June 9, 2013, 00:26
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Dear Sina,

I got the status after I check mesh quality in Fluent. Please find the picture. thank you
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Old   June 9, 2013, 00:37
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Its seem that your mesh quality have't any problem. you can use orthogonal meshing to avoide this error. but dont worry! run your case without any mesh repairing.
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Old   June 9, 2013, 00:48
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Thanks Sina.

I will not use mesh/repair-improve/improve-quality in Fluent. Because my case can run and get result without repairing mesh. I got the problem after I repaired. So I though my mesh have mistakes. Thank you
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Old   December 30, 2013, 03:42
Default mesh problem
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mariana
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dear Loi and Sina,
i have the same problem as you did but my report from quality test was different. i am attaching you the photo. Can you help me? can you understand where is the problem?
thank you
and i hope that somebody will know the how to solve my problem
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Old   December 30, 2013, 03:45
Default mesh again
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i run again my mesh in fluent and i had this message :
Divergence detected in AMG solver: x-momentum -> Increasing relaxation sweeps!

Error: Divergence detected in AMG solver: x-momentum
Error Object: #f
do you know what is it?
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Old   December 30, 2013, 07:11
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divergence starting from the impuls in x direction!

Check up settings and Boundaries
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Old   December 30, 2013, 07:19
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thank you, i understood that too. should i do it in the geometry step? or in mesh? or is it the same?
thank you
best regards
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Old   December 30, 2013, 07:24
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You have zero minimum orthogonal quality and huge aspect ratios! Start improving the mesh and please do that in your mesher.
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Old   January 2, 2014, 12:13
Default mesher
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mariana
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hello and happy new year!
what do you mean repair mesh in your mesher????
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Old   January 2, 2014, 12:22
Default mesh quality
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mariana
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dear Zaktatir,
sorry that i am bothering again and again but i really do not understand where is my problem( i just start to learn fluent).
so i have to check boundaries in mesh step yeap? and which are the limits so i would know that my mesh is ok?
thank you very much
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Old   January 2, 2014, 12:27
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You have to deliver a better mesh. I don't know which program you are using to build up the numerical domain that's why i said pre-processing program. You geometry is not difficult to deliver a better meh
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Old   January 8, 2014, 04:07
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sina
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Dear Mariana
what is your software for meshing?
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Old   January 8, 2014, 11:45
Default hello and happy new year!!!
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I have ansys fluent 14.0. and i am working mesh there. in my pc i have windows 7. the geometry i made in rhino.
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Old   January 11, 2014, 01:38
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sina
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Dear Mariana

Please try to use structural Mesh in ANSYS Meshing to avoid this error.
Regards
sina
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Old   January 11, 2014, 06:21
Default mesh
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dear Sina,
i will try
thank you
br
mariana
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