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-   -   how to calculate the porosity flow rate? (https://www.cfd-online.com/Forums/openfoam-pre-processing/145939-how-calculate-porosity-flow-rate.html)

Heremus December 15, 2014 15:06

how to calculate the porosity flow rate?
 
Hello I need fast help and unfortunatly i found nothing in my search (thats is unusual :(). My solution doesn't work.

My case is incompressible and isothermal. I have a porous zone where I want to calculate the porosity more or less so that I get a certain flowspeed in that area.

I took the equation from the Darcy Forchheimer header file.

S = - (mu*d + 0.5*rho*UČ*f)

I assumed that S is a force and flow only flows in one direction so I took the U into the brackets.

So I thought about setting d to zero and using a bernulli equation to substitute S.

S = - deltaP * A =- 0.5*rho*(UČ-UČ_after)*A

After substituting this I relocated it to f:

f = A*(1-UČ_after/UČ)

But it doesn't work. The values are to low. So what all do I wrong.

Thanks for every help!


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