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pressure ratio between two parallel walls ??

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Old   July 5, 2008, 10:10
Default pressure ratio between two parallel walls ??
  #1
frank
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Hi,

I just simplify my question as:

I have two paralle node-to-node walls in my flow field. Now, I want to have the pressure ratio between the two walls. That is

P_i(wall1)/P_i(wall2)

Can I have this parameter in cfx solving process?

Thanks for your reply.

frank
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Old   July 6, 2008, 23:54
Default Re: pressure ratio between two parallel walls ??
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Glenn Horrocks
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Hi,

Write it to a monitor point with the CEL expression. Then you see it in Solver manager as the simulation progresses.

Glenn Horrocks
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Old   July 7, 2008, 23:17
Default Re: pressure ratio between two parallel walls ??
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frank
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Thanks for your reply,Glenn Horrocks

How to use CEL for two different surfaces,although they have the same number of nodes?

something like this?

P@surface1/P@surface2

This syntax seems unlawful for CEL.

pls give more hints about this.

Thanks
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Old   July 7, 2008, 23:25
Default Re: pressure ratio between two parallel walls ??
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Glenn Horrocks
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Hi,

Try something like "areaAve(p)@surface1". The syntax of the CEL language is detailed in the CFX reference manual.

Glenn Horrocks
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Old   July 8, 2008, 00:39
Default Re: pressure ratio between two parallel walls ??
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frank
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To Glenn Horrocks I know this function,this will give out the average ratio of surface1's and surface2's pressure in a whole, not the pressure ratio of the on node to node base. Suppose we have N nodes for each surface, what I want is to get N ratio values.That is to say it is a distribution function.

But thank you all the same.

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Old   July 8, 2008, 19:23
Default Re: pressure ratio between two parallel walls ??
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Glenn Horrocks
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Hi,

What are you trying to do? Exactly what do you want the pressure ratio of?

Glenn Horrocks
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Old   July 8, 2008, 23:37
Default Re: pressure ratio between two parallel walls ??
  #7
frank
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Hi,

I am modeling the phenomena of concentration overpotential in fuel cell porous media which will depend on the pressure ratio of two boundaries.

Similar case happen to the surface electric resistence for two connecting surfaces. There will be a electric potential jump between the two surfaces, which we should use the potential of one surface and the potential jump to express the other surface's electric potential.

So, I find this is a fault of cfx of disability to refer variables at two different places, even at domain interface.
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