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-   -   Setting up a porous media (http://www.cfd-online.com/Forums/star-cd/77511-setting-up-porous-media.html)

en51nm June 25, 2010 04:29

Setting up a porous media
 
Hi all,

I've been having some trouble setting up a porous media flow in Star-CD v4 through a porous baffle. I know the force ({F_p}) and hence the pressure drop across the baffle and I need to calculate {\alpha} and {\beta}:

{\Delta p = - \rho ( \alpha \upsilon + \beta ) \upsilon}

where {\upsilon} is superficial velocity and {\rho} is fluid density (I assume).

I seem to have too many unknowns, since I do not know the superficial velocity... any ideas would be greatly appreciated.

olauer June 25, 2010 08:15

But you know pressure drop for a given mass flow. And you now the area of your porous baffle, and the density. So you can calculate a mean velocity. Better would be to have pressure drops for more than one mass flow because you have two unknowns

Pauli June 25, 2010 10:32

You have one equation with two unknowns. You need the force/pressure drop at two or more flow rates. Then you can curve fit the equation to the data.

en51nm June 25, 2010 10:42

I have one force value, but I don't have an associated flow rate for that force. How can I calculate the flow rate in the porous media?


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