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inlet/outlet settings on symmetric analysis

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Old   October 14, 2014, 19:52
Question inlet/outlet settings on symmetric analysis
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Hi,

for fluent flow BCs how can i define outlet area if the area is on the symmetric side as shown below

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Old   October 14, 2014, 22:43
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Hello Sozen,

This geometry is not symmetric, since there is a flow crossing your current 'symmetry plane'. In order to make the geometery symmetric, you need to make the cut horizontal, instead of vertical as it is now (I assume the geometry is 2D?) Then you can simply specify a velocity inlet with the same velocity as usual (so it gets half the total volumetric flow) and a pressure outlet.

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Cees
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Old   October 15, 2014, 00:29
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Hello Sozen,

This geometry is not symmetric, since there is a flow crossing your current 'symmetry plane'. ...
Thank you for your advise Cees,
Does this means "the flow have to be symmetric in symmetry method"?

So, let's assume the problem is two flanged pipe and there are two symmetric fans inside the flanged area(3d). Can't we solve this with symmetry method?
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Old   October 15, 2014, 02:06
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Indeed, the flow has to be symmetric in order to exploit symmetries.

You can indeed use symmetry on a flanged pipe with some kind of fan in there, provided it is symmetric. For example, if the fan has 6 blades, you might model only 1 blade, and a 60 degree section of the pipe, and assume a periodic symmetry.

Best,
Cees
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Old   October 15, 2014, 02:21
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Quote:
Originally Posted by CeesH View Post
Indeed, the flow has to be symmetric in order to exploit symmetries.

You can indeed use symmetry on a flanged pipe with some kind of fan in there, provided it is symmetric. For example, if the fan has 6 blades, you might model only 1 blade, and a 60 degree section of the pipe, and assume a periodic symmetry.

Best,
Cees
i don't know if i can use the periodic symmetry due to helix shaped blades and small gaps between them. But i'll try, thanks a lot.
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Old   October 15, 2014, 03:19
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Helix shaped blades may indeed be a problem.. Anyway, good luck!
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