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axisymetric-WARNING:non-positive face area exist

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Old   November 9, 2005, 14:36
Default axisymetric-WARNING:non-positive face area exist
  #1
JORDI
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i've got an error checking the grid in an axysymetric problem in 2d. the x axis is my revolution axis and i don't understand why i have a zero face area.(using fluent 6.2.16 )

can anybody help me--thanx a lot in advance.JORDI ARMENGOL

Grid Check

Domain Extents:

x-coordinate: min (m) = 0.000000e+000, max (m) = 5.000000e+001

y-coordinate: min (m) = 0.000000e+000, max (m) = 2.000000e+002 ...

WARNING: non-positive face area exist.

minimum face area (m2): 0.000000e+000

maximum face area (m2): 7.691770e+002
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Old   November 9, 2005, 14:50
Default i foget
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JORDI
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that if i check the grid with 2d solver (not axisymetric) i won't give the error -- the grid check is ok

sorry
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Old   November 9, 2005, 15:24
Default Re: i foget
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KP
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check BC, skeweness, and also check the box Import 2d mesh while exporting it from Gambit. KP

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Old   November 9, 2005, 17:39
Default Re: i foget
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JORDI
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it's a very simple problem with only two bc. and i have done similar models and i think it is not the problem. i always have the box "import 2d mesh" but i dont know how to check the skewness (i don't know whats skewness) can you give me some notes thanx. JORDI
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Old   November 10, 2005, 07:52
Default Re: i foget
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KP
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length to breadth ratio of a single cell should be less than 5:1. This is mantained in order to avoid numerical diffusion. Higher order numerical schemes can also be tried but defaults are best suited for most of the cases.

Check your case. I presume something wrong with BC ... KP
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Old   November 10, 2005, 09:19
Default Re: i foget
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JORDI
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i don't know what to do with BC. i have checked the mesh without the axysymetric solver (with 2d) and the result is ok? what can happenb to my model? thanx again.
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Old   November 10, 2005, 10:24
Default Re: i foget
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Alec Eiffel
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axi symmetric models must have the axis of rotation on the cartesian x-axis. I think this may be the problem. hope this helps
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Old   November 10, 2005, 10:45
Default Re: axisymetric-WARNING:non-positive face area exi
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hongfw
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Open the Grid/Translate, check if the the Ymin is less than zero. If it is, translte the grid making the Ymin equal to zero.
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Old   November 10, 2005, 13:41
Default x axis of rotation
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JORDI
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thanks but the x axis is my rotation axis indeed. i don't know... thanx again
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Old   March 9, 2011, 06:15
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MOHSEN Zendehbad
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Dear friend, were you finally able to solve this problem? we're facing the same problem now!
mohsen zendehbad is offline   Reply With Quote

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