CFD Online Discussion Forums

CFD Online Discussion Forums (http://www.cfd-online.com/Forums/)
-   FLUENT (http://www.cfd-online.com/Forums/fluent/)
-   -   Negative cell volume problem (http://www.cfd-online.com/Forums/fluent/93841-negative-cell-volume-problem.html)

schuny October 27, 2011 16:10

Negative cell volume problem
 
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?

roukaia November 1, 2011 15:15

i have the same problem
the negative cell volume exists when i preview the apdating the mesh
have you found the problem

mvee November 2, 2011 04:01

negative volume
 
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.

Regards
mvee

roukaia November 3, 2011 14:58

thank you for replying

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

regards

mvee November 5, 2011 04:09

-ve volume
 
You can solve any problem based on smoothing and remeshing.

roukaia November 5, 2011 11:52

GAMBIT :structured & unstructured mesh in one face
 
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

roukaia November 5, 2011 11:59

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

roukaia November 5, 2011 12:02

need help for meshing in gambit
 
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

mvee April 10, 2012 05:16

solution
 
Hi

Did you solve the issue? Pl update me.

Regards
mvee


All times are GMT -4. The time now is 05:44.