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October 25, 2019, 09:39 |
How to apply porosity setting?
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#1 |
Senior Member
Aja
Join Date: Nov 2013
Posts: 496
Rep Power: 14 |
Hi,
I have one porous media in my computational domain. But I face with error related to porous media. I am sure that this error is depended on setting of porous media domain. The porous domain has different options that I don't know that how to setting up those options. How can I compute these options? I am grateful that that guide me in this case or give me some ideas or useful papers/sites to solve this problem. I apply porosity setting as follows: Error is as follows: |
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October 25, 2019, 20:17 |
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#2 |
Super Moderator
Glenn Horrocks
Join Date: Mar 2009
Location: Sydney, Australia
Posts: 17,665
Rep Power: 143 |
While it is possible that the porous domain is linked to the floating point error, you should read the floating point error FAQ to make sure you have the general background on the issue: https://www.cfd-online.com/Wiki/Ansy...do_about_it.3F
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Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum. |
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October 28, 2019, 04:19 |
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#3 |
Senior Member
Gert-Jan
Join Date: Oct 2012
Location: Europe
Posts: 1,818
Rep Power: 27 |
Looking at the timescale of your simulation (87000 s = ±1 day), I think one of your BC-settings is wrong. Possibly you only set pressures? It might help to set an initial velocity scale as initial guess to help CFX to determine the auto-timescale more accurate, or use physical timestepping.
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October 28, 2019, 08:43 |
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#4 |
Member
Abdullah Arslan
Join Date: Apr 2019
Posts: 94
Rep Power: 6 |
For calculating interfacial area density and loss coefficient, there are formulae. But they depend on level of porosity. The ones valid for low porous, like .7, are not valid for highly porous medium like of value 0.95.
Similarly it depends on size of porous medium. Like 2mm thick foam behaves very different from 10mm even the 2mm was part of same parent foam. |
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October 29, 2019, 10:05 |
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#5 | |
Senior Member
Aja
Join Date: Nov 2013
Posts: 496
Rep Power: 14 |
Quote:
Could you please give me link/ducument about formulae? |
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October 29, 2019, 10:27 |
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#6 |
Member
Abdullah Arslan
Join Date: Apr 2019
Posts: 94
Rep Power: 6 |
There are many paper.. Anyway, send me an email. muhammad.arslan@mail.bcu.ac.uk
It is better always, to look for a book/paper where they have given data of each parameter instead of calculating it by yourself. |
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