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Left-handed faces due to non-convex cells?

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Old   June 20, 2009, 09:12
Default Left-handed faces due to non-convex cells?
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Hi!

When performing grid check in Fluent, I got the message "Warning: Grid check failed". Neither Fluent nor Gambit reported negative volumes or faces. When I typed "/grid/modify-zones/repair-face-handedness", I got this message instead:
"Left-handed faces can't be converted to right-handed faces.
All face nodes have the right order, but the mesh probably
contains non-convex cells."
What does this mean and how to resolve this? Thanks!
P.S.: I've tried smoothing the mesh, but it only increased the number of left-handed faces
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Old   July 28, 2009, 10:44
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Dimitrios Mylonas
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I have the same problem as you and tried the same alternative but nothing; although smoothing the mesh did not increase the left-handedness in my case.
I have a positive volume and the highest skewness is 0.97 which usually is ok to go through but in this particular case, I can't get rid of this problem.
Any help welcome! Thank you
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Old   July 28, 2009, 11:38
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Hi Dimitrios,

I actually managed to solve the problem by increasing the height of the domain to be meshed with respect to the width (my simulation was an external flow over an object problem, so the meshed domain was the fluid domain box). In my case, I'm free to change the domain dimensions - I'm not sure if this applies to your problem, but if it does, perhaps you could give it a try and see if it works? Good luck! :-)

Regards,
Crystal
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Old   July 31, 2009, 08:41
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HI

Crystal

If you have meshed it in gambit with coopering options and then tet mesh generation.
Try out this

Delete all the volume mesh from Gambit and try mesh the geometry from one end whatever type of mesh you put in the geometry it should start from one end of the geom and stop at other end. i.e. do not intermittently mesh the different zone.
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