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How do you set up a porous region

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Old   June 22, 2010, 07:02
Default How do you set up a porous region
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james charlton
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Hi,

Im a little confused on how to correctly set up a porous region. I know how to create a porous region. But im confused on what interface i should use (porous baffle?), Also how do you calibrate the settings - i.e. to have a 50/50 and 70/30 porous region? Any advice would be appreciated.

regards

James
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Old   June 25, 2010, 02:11
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Read the manual.
It's very simple! Maybe you have to read the expression more than one time but with a little excel sheet you can set the pressure drop you need.
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Old   June 29, 2010, 10:17
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james charlton
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Thanks Maddin, but by the manual, do you mean the help files?

I've looked there and no luck.

Any chance you could expand you answer
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Old   June 29, 2010, 10:20
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No the help files are only a "little" manual.
You should have some pdf-files in your ccm directory.
2000 pages strong... there you find all you need!
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Old   June 29, 2010, 10:27
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ah...... i didnt know this existed. Thanks maddin.... this could answer several of my questions!!! (i hope)
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Old   July 5, 2010, 08:00
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Niaz Ali Ahmed
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There is a tutorial called Porous Flow. Go to Help>Training Guide. You may use an In-Place interface too.
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Old   July 5, 2010, 08:19
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Thanks Niazaliahmed - I am using In-place interfaces now. I have a volume mesh and porous region. I just dont know what to do then - i.e. in the physics values in the porous region. I see there is a porosity setting (constant) which as default is set at one. I've tried changing this value to numerous values between 0 - 1.0 but nothing seems to work.

- I have tried the tutorial

If i apply the same process - i.e. Axisymetric Tensor; and random Pi and Pv values i do get a result. But i cannot validate this process or values or the accuracy of the given results.

Any further suggestions would be gratefully appreciated.
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Old   July 5, 2010, 11:11
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Vinicius Girardi
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The value of porosity just have effect when you are running unsteady simulations, if you are running steady, just set the Porous Inertial Resistance and Viscous Resistance.
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Old   July 5, 2010, 11:15
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@Vinicius - Thank you. Thats fine. So i guess the next question is which Tensor you use? Following this i need to establish accepted values for initial and viscous resistance for trees.
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Old   July 6, 2011, 17:39
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Hey James,

Given a geometry, how to create a porous region from it? Thank.
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Old   July 6, 2011, 17:44
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Sorry, i dont understand you question.
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Old   July 7, 2011, 05:54
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Quote:
Originally Posted by charltonjames View Post
@Vinicius - Thank you. Thats fine. So i guess the next question is which Tensor you use? Following this i need to establish accepted values for initial and viscous resistance for trees.
Hi James

You've to choose the tensor according the flow direction in the porous region and its geometric characteristic.
you have to know if the porous region is isotropic un-isotropic, axial-symmetric etc.
For Inertial and Viscous resistance values you must have a characteristic curve (velocity/DP or similar) of the considered material.
If you need further help please describe your problem in detailed way

by
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Old   July 15, 2011, 14:15
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Quote:
Originally Posted by charltonjames View Post
Sorry, i dont understand you question.
I mean do you know how to create a porous region including boundary and interface? Currently I have three parts vertically connected to each other, say A, B and C. B is the porous region which is sandwiched by A&C.

I just have no idea how to set B as a porous region and what parameters I need although I've read through that porous region tutorial...

Any help would be appreciated.
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Old   August 13, 2011, 18:29
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Quote:
Originally Posted by Scibor79 View Post
Hi James

You've to choose the tensor according the flow direction in the porous region and its geometric characteristic.
you have to know if the porous region is isotropic un-isotropic, axial-symmetric etc.
For Inertial and Viscous resistance values you must have a characteristic curve (velocity/DP or similar) of the considered material.
If you need further help please describe your problem in detailed way

by
Can I calculate those two resistance values based on the equation the tutorial provides? Thanks.
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