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Old   June 17, 2008, 11:13
Default Left handed Cells
  #1
AndyR
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Folks, Have a 7.1 million cell model I built in Gridgen. Passes all checks in that tool. Fluent is complaining about 18 Left Handed Cells in five different zones. The zones it references do not seem to match zones applied to fluid volumes or face zones.

Any good ideas on tracking down where fluent things the problem is? This lack of the obvious makes me really question those who claim this tool is easy to use!!

Any help is appreciated.

Thanks - Andy R (I miss Prostar!!)
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Old   June 17, 2008, 13:45
Default Re: Left handed Cells
  #2
red lemon
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Try TUI command to fix left handed faces in Fluent
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Old   June 17, 2008, 15:05
Default Re: Left handed Cells
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Andy R
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Thanks, I managed to fix the problem by looking for the negative volume cells. Then going back to gridgen and doing a little smoothing. It just seems odd that Fluent will reference a zone and not be able to somehow graphically display that zone. Just as it seems odd that it tells you there are negative volume cells but not how many or where.

That would seem to be useful information

Thanks anyway - Andy R
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Old   June 17, 2008, 15:14
Default Re: Left handed Cells
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red lemon
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you could read the case file into TGrid and you can display left handed elements in that software.
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Old   June 19, 2008, 14:19
Default Re: Left handed Cells
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BastiL
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...as long as it does not contain polyhedrals....
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Old   June 19, 2008, 14:25
Default Re: Left handed Cells
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red lemon
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correct. TGrid cannot read polyhedral grids or adapted grids though it can read non tpoly'd hexcore grids.
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Old   June 19, 2008, 14:33
Default Re: Left handed Cells
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BastiL
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However, saving it as Polyhedral mesh is highly recommended (as FLUENT message says) and default in T-Grid.
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Old   June 19, 2008, 16:39
Default Re: Left handed Cells
  #8
red lemon
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yes poly conversion is recommended for hexcore. This is because it prevents non conformals but has drawbacks. Converted meshes cannot be read into Tgrid and some post tools like FieldView cannot see poly elements. Also you cannot do moving/deforming meshes or adaption with poly meshes.
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Old   June 29, 2008, 10:52
Default Re: Left handed Cells
  #9
AAJ
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Dear AndyR

If u still have that problem with the Left handed cells, u might need to go back to grid gen, grid gen wont tell u about left handed cells or faces. Its some kind ov topology problem, u r lucky if u have smaller number of blocks in ur problem. two things u can do to remove this problem. 1- Either delete all the blocks (but dont delete domains and connectors) and form the blocks again. hope this will solve the problem, but it is recomended if u have lesser number of blocks.

2- When u modify the block u can specify zeta,eta etc on the block. these zeta,eta,etc cordinates define whether the block is left handed or right handed. when u specify these cordinates on block it will tell u whether the block is right handed or left handed. try changing their directions and interchanging them on block edges. becareful changing these cordinates may result in a block with all negative volumes.
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