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Old   October 27, 2011, 16:10
Default Negative cell volume problem
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dandan xiao
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I'm doing a dynamic mesh simulation with in-cylinder combustion. My mesh is OK when imported into fluent. However, I got this error after several itterations:
Updating mesh to time 4.00000e-04 (step = 00045) (crank-angle = 184.80)...
Warning: non-positive volumes exist.

Error: Update-Dynamic-Mesh failed. Negative cell volume detected.
Error Object: #f
How can I fix this?
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Old   November 1, 2011, 15:15
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Boudour
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i have the same problem
the negative cell volume exists when i preview the apdating the mesh
have you found the problem
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Old   November 2, 2011, 04:01
Default negative volume
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Vaze
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Hi schuny and roukaia

Please follow the strategy given in the tutorial on piston displacement because for such problem there should not be any problem.

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mvee
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Old   November 3, 2011, 14:58
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thank you for replying

do you mean the tutoriel of dynamic mesh (smoothing layering )

regards
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Old   November 5, 2011, 04:09
Default -ve volume
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You can solve any problem based on smoothing and remeshing.
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Old   November 5, 2011, 11:52
Default GAMBIT :structured & unstructured mesh in one face
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dear mvee
yes i agree with you but i have also the layering method wich need a structured mesh (the layering zones valves must be in quadr)
there is a joint piece for more details Attachment 9871
please have you got any idea about how to construct (a structured & unstructured mesh in one face in gambit because i think that 's the main problem of negative volume

any will be appreciated

Last edited by roukaia; January 9, 2012 at 13:52.
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Old   November 5, 2011, 11:59
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more details about my mesh and even the error in the joint piece

Updating mesh to time 3.88889e-04 (step = 00007) (crank-angle = 363.50)...
Warning: negative volume detected --> repeat smoothing!
Warning: negative volume detected --> repeat smoothing!
Warning: negative volume detected --> repeat smoothing!
Warning: non-positive volumes exist.

Error: Update-Dynamic-Mesh failed. Negative cell volume detected.
Error Object: #f

Last edited by roukaia; January 9, 2012 at 13:52.
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Old   November 5, 2011, 12:02
Default need help for meshing in gambit
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more details about my mesh in the joint piece

Updating mesh to time 3.88889e-04 (step = 00007) (crank-angle = 363.50)...
Warning: negative volume detected --> repeat smoothing!
Warning: negative volume detected --> repeat smoothing!
Warning: negative volume detected --> repeat smoothing!
Warning: non-positive volumes exist.

Error: Update-Dynamic-Mesh failed. Negative cell volume detected.
Error Object: #f

Last edited by roukaia; January 9, 2012 at 13:52.
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Old   April 10, 2012, 05:16
Default solution
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Hi

Did you solve the issue? Pl update me.

Regards
mvee
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