CFD Online Logo CFD Online URL
Home > Forums > Software User Forums > ANSYS > FLUENT

Porosity PPI : how convert in % ?

Register Blogs Members List Search Today's Posts Mark Forums Read

Like Tree4Likes
  • 1 Post By Rich1979
  • 3 Post By samuraiufrn

LinkBack Thread Tools Search this Thread Display Modes
Old   March 29, 2011, 10:39
Default Porosity PPI : how convert in % ?
Join Date: Dec 2009
Posts: 41
Rep Power: 16
Rich1979 is on a distinguished road
Hi all,
i have a question about modeling a porous media.
I have as information for my porous media its PPI , pores per inch(40 or 50 foe ex.).
Fluent input for porosity is instead in % (fluid volume/media volume).
How could i convert ppi to percentage?
Thanks mates likes this.
Rich1979 is offline   Reply With Quote

Old   February 15, 2012, 10:03
New Member
Josť Eduardo
Join Date: Jun 2010
Posts: 1
Rep Power: 0
samuraiufrn is on a distinguished road
You must have at least two of these four informations: porosity, mean pore diameter, mean particle diameter and pore density. You can relate mean pore diameter and mean particle diameter with the expression:


If you already have the mean particle diameter value, you can use this expression directly:

Poredensity (ppcm)=(300/Dparticle)*sqrt[(1-porosity)^2/(porosity*pi)]

All diameters given in meters. It's easy to deduce these expressions if you consider one particle for each pore and consider the porous media as arranjed spheres. Another hint is if you have the permeability (K) value and mean particle diameter, so using Ergun's expression, you got:


Where b=144 for most porous cases.
vbnhfylbh, moeinvh and like this.

Last edited by samuraiufrn; February 15, 2012 at 10:36.
samuraiufrn is offline   Reply With Quote


Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On

Similar Threads
Thread Thread Starter Forum Replies Last Post
Porosity field in Fluent wojciech FLUENT 1 September 20, 2010 11:19
UDF for porosity Giacomo FLUENT 3 July 23, 2007 09:23
porous media with variable porosity Kevin A. FLUENT 3 December 24, 2006 10:56
porosity of baffle raymond Siemens 4 April 4, 2002 04:03

All times are GMT -4. The time now is 09:03.