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-   -   [GAMBIT] (HELP!) Gambit volume meshing error, Initialization failed, Perturbation boundary (https://www.cfd-online.com/Forums/ansys-meshing/84949-help-gambit-volume-meshing-error-initialization-failed-perturbation-boundary.html)

 sincity February 13, 2011 03:22

(HELP!) Gambit volume meshing error, Initialization failed, Perturbation boundary

i'm trying to modeling 3D SYMMETRY BUTTERFLY VALVE, but i keep continue get an error message: "Initialization Failed, Perturbation Boundary..", from GAMBIT while i'm trying to mesh it. how can i solve this??please help!thanks.
( i can send you my 3D GAMBIT model)

 -mAx- February 14, 2011 02:53

post a picture

 sincity February 14, 2011 09:06

http://img831.imageshack.us/img831/305/theproblem.jpg[IMG]file:///C:/the%20problem.jpg[/IMG]
here is my problem max..area in the circle that i cannot mesh it. i can send you my GAMBIT file if you want to help me

 -mAx- February 14, 2011 11:05

The problem comes from your cylinder.
Indeed with this diameter, you have a problem at the top of your butterfly valve, because exactly on y-axis your valve has also same diameter.
Then you have very sharp angle which will crash meshing-process.
check edge.228 & edge.10

 sincity February 14, 2011 11:33

le

i know that max...that's the problem,
since i'm working with my butterfly valve with 75 degree opening angle model. i've tried in so many way but i couldn't find the solution, split it, reducing internal size, using size function, mesh edge..but they gave me the same error skewness.
how could i possible to mesh it succesfully, max?

 -mAx- February 14, 2011 13:05

you can, for instance, increase the cylinder diameter (very small change in diameter), just for allowing one cell layer between cylinder and valve..
Than can be also a local extrusion, just in the neighborhood from rotation axis.
Anyway you need to change your topology

 sincity February 15, 2011 00:47

Quote:
 Originally Posted by -mAx- (Post 295212) you can, for instance, increase the cylinder diameter (very small change in diameter), just for allowing one cell layer between cylinder and valve.. Than can be also a local extrusion, just in the neighborhood from rotation axis. Anyway you need to change your topology

but is that ok if i change the dimension of my model??

 -mAx- February 15, 2011 02:08

If you increase the cylinder diameter, you may also increase the "leakage" above the valve.
But as I said increase, I meant a very small change (in your tolerance)
If you think the gap is too important in respect of leakage, then you can split your domain at the valve (as you already did), an turned as small portion of your split surface as wall

 sincity February 15, 2011 07:37

i get it, thanks max..by the way, could i email you if i have trouble again??

 -mAx- February 15, 2011 07:52