# How to apply porosity setting?

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 October 25, 2019, 09:39 How to apply porosity setting? #1 Senior Member   Aja Join Date: Nov 2013 Location: Iran Posts: 492 Rep Power: 10 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:

 October 25, 2019, 20:17 #2 Super Moderator   Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 16,404 Rep Power: 127 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 aja1345 likes this. __________________ Note: I do not answer CFD questions by PM. CFD questions should be posted on the forum.

 October 28, 2019, 04:19 #3 Senior Member   Gert-Jan Join Date: Oct 2012 Location: Europe Posts: 1,192 Rep Power: 18 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. aja1345 likes this.

 October 28, 2019, 08:43 #4 Member   Abdullah Arslan Join Date: Apr 2019 Posts: 92 Rep Power: 3 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. aja1345 likes this.

October 29, 2019, 10:05
#5
Senior Member

Aja
Join Date: Nov 2013
Location: Iran
Posts: 492
Rep Power: 10
Quote:
 Originally Posted by Goenitz 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.

October 29, 2019, 10:27
#6
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Abdullah Arslan
Join Date: Apr 2019
Posts: 92
Rep Power: 3
Quote:
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.