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-   -   Interfacial area density while setting in the porous domain (http://www.cfd-online.com/Forums/cfx/110586-interfacial-area-density-while-setting-porous-domain.html)

 kmgraju December 14, 2012 23:02

Interfacial area density while setting in the porous domain

Dear friend

For example
I have straight pipe which is porous domain of inner radius 10mm and thickness of the wall 3mm
and length of the pipe is 100mm through which fluid flow through it
How to calculate inter-facial area density
I did this way
Inter facial area density= surface area contact/ Volume

surface area= 2*pi*r*h/pi *r^2*h

=2*pi*10*100/ pi*10^2*100

= 2/10 mm^-1

Thank you

Regards

Govind
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 kmgraju December 15, 2012 10:19

Dear friends
I did Catalytic converter tutorial. I am in doubt how they set interfacial area density 360 m ^-1
Thank you

Regards
Govind

 cdegroot December 15, 2012 10:51

Interfacial area density is the amount of surface area per unit volume. The value for metal foams, for example, is usually in the thousands. 360m^-1 could be reasonable for a catalytic converter. Note how this wouldn't be constant if a pore shape is scaled down. If the formula is A/V and you scale down by a factor of two, the interfacial area density doubles. Therefore this number is higher for smaller pore sizes.

 kmgraju December 15, 2012 13:12

Quote:
 Originally Posted by cdegroot (Post 397680) Interfacial area density is the amount of surface area per unit volume. The value for metal foams, for example, is usually in the thousands. 360m^-1 could be reasonable for a catalytic converter. Note how this wouldn't be constant if a pore shape is scaled down. If the formula is A/V and you scale down by a factor of two, the interfacial area density doubles. Therefore this number is higher for smaller pore sizes.
Dear friend cdegroot
Can you please explain bit with catalytic converter.
This 360 m^-1 is randomly assigned or any approximate calculation to arrive this.If there is a calculation to arrive this value please share with me
if I don't know how to get interfacial area density through calculation, How do I fix my interfacial area density for my model ?( porosity value known).
Thank you for spending your precious time for me.

Thank you
Govind

 cdegroot December 15, 2012 15:46

I think the 360m^-1 is randomly assigned as a quasi-reasonable value for a catalytic converter. To determine your interfacial area density you need to know something about your pore shape (is it a packed bed, tube bundle, foam, etc) and the pore size. If it's a common shape you should be able to find data for it. If not, come up with a simplified model and calculate it.

 kmgraju December 15, 2012 22:27

Dear friend

I need to put interfacial area density in my arterial modelling. I know the porosity and permeability value.
Is there any way to calculate interfacial area density. I am also searching the data available in the journal

Thank you

Regards
Govind

 cdegroot December 15, 2012 23:05

There is no way to calculate just knowing permeability and porosity. I think you may be able to find something in the literature to help you.

 cdegroot December 15, 2012 23:20

If you are doing bioheat modeling here is a good review with a simple expression for interfacial area density.

http://th1a8.eng.shizuoka.ac.jp/~hea...g%20Theory.pdf

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