# Porous Media modeling

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April 24, 2014, 04:00
#21
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Quote:
 Originally Posted by nelly Hi Oky, did you get to find the parameters? If not, here is the explanation. The formula is Dp/L= [(viscosity/alpha)*velocity]+ [C2*1/2*density*velocity^2] (dp/l =viscousr resistance + inertial resistance) and plot dp/l vs velocity in excel. The pressure drop can be obtained from cfd. The values for velocity can be arbitrarily chosen say for ex. 0 to 20 m/s (even more if you want more points) Plot Dp/L vs velocity based on above formula and examine the curve how it looks like. If it is a straight line then use only dp/l=viscous resistance. If it is a quadratic equation use (dp/l =viscousr resistance + inertial resistance). Find K and C2 with these curves. Hope this helps . cheers Nelly
Hi Nelly,

I did everything you specified above I only have two clarifications.

1.) I sometime get a negative k=permeability because when I plot DeltaP vs Velocity it gives me an equation with a -Bx. My question is, can I use this (-) Value of k as input? if not please give me a hint on how to remedy this problem.

2.) To get C2 and k you have to use L=Thickness. My question is what thickness to use?, the thickness of the screen which you got the experimental data from ,(P vs V), or the representative porous media's thickness used in the solver (I some times use thick Porous media for ease of meshing)

Thanks.

-will

 August 19, 2014, 02:32 Details of Porous Media #22 New Member   Jeeban Poudel Join Date: Apr 2014 Posts: 3 Rep Power: 9 Hello, I am trying to understand and operate a porous media in which the void fraction is arranged in random order. Whenever I select the system as laminar, the flow is laminar and even when I select it to be turbulent, the flow is laminar. So, what are the factors we need to consider (it is very complicated to consider all points) to simulate the random arrangement of the void fraction? Further which parameters are normally selected and avoided while considering the porous media.

 October 5, 2014, 16:16 porous media #23 New Member   usamaraad Join Date: Oct 2014 Posts: 5 Rep Power: 9 hi for all I need to know the steps of build up a porous media by using fluent program I need for these steps too much so I wish form any one who can present the assistance to support me please

 July 20, 2015, 15:48 #24 New Member   mohamadreza Join Date: Jul 2015 Posts: 16 Rep Power: 8 Hi every body I don't know how determine initial velocity for the flow in porous media. Thank you for time and consideration. Best regards arnie333 likes this.

 July 21, 2015, 07:29 #25 New Member   Mayur Bhandari Join Date: May 2015 Posts: 8 Rep Power: 8 Hello Rupak Banerji, In your first message you said about tutorial number 8. Which series of tutorial you are solving? can you share?

 December 28, 2017, 08:50 modelling porous surface #26 New Member   vasu Join Date: Dec 2017 Posts: 3 Rep Power: 5 Hey friends how do i model a porous surface in ansys fluent? can i make a wall surface porous need help thanks in advance

December 28, 2017, 15:22
#27
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i man
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Quote:
 Originally Posted by vasudev1997 Hey friends how do i model a porous surface in ansys fluent? can i make a wall surface porous need help thanks in advance
It's simple, just set the "porous jump" to a zero thickness wall and fill the coefficients.

December 28, 2017, 21:11
#28
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vasu
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Quote:
 Originally Posted by chocolater It's simple, just set the "porous jump" to a zero thickness wall and fill the coefficients.

 January 4, 2018, 04:00 #29 Member   tahir Join Date: May 2010 Posts: 35 Rep Power: 13 hi Nelly. you said that pressure drop can be calculated from CFD. I am working on combustion of heptane gas through porous medium. In this case how can i calculate the porous coefficient. Your help is really needed.

 October 4, 2019, 14:32 Porous media #30 New Member   Somesh Join Date: Oct 2019 Posts: 3 Rep Power: 4 The Velocity in porous media shows the same as inlet pipe. Is their any difference in velocity in porous media and the velocity in empty pipe??

 October 4, 2019, 14:35 Porous media #31 New Member   Somesh Join Date: Oct 2019 Posts: 3 Rep Power: 4 Is their velocity difference in porous media and the empty pipe. I doing simulation in ansys. Using physical velocity but i didnt se the difference in velocity

 Tags gambit, porous