Porous media modelling

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 September 13, 2013, 11:31 Porous media modelling #1 New Member   Anonymous Join Date: Jun 2013 Posts: 9 Rep Power: 10 I am trying to model a porous filter which has Plasma (blood) fluid passing through it . I am trying to find the (A) Inertial coefficient α(kg/m4) and (B) Viscous coefficient β(kg/(m3s) How to calculate these co-efficients? any suggestion > help plz

October 3, 2013, 09:22
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Rami Ben-Zvi
Join Date: Mar 2009
Posts: 154
Rep Power: 14
Quote:
 Originally Posted by dreamlifter747 I am trying to model a porous filter which has Plasma (blood) fluid passing through it . I am trying to find the (A) Inertial coefficient α(kg/m4) and (B) Viscous coefficient β(kg/(m3s) How to calculate these co-efficients? any suggestion > help plz
The inertial and viscous resistance coefficients are usually measured for the specific porous medium (pore size, pore density, pore shape, ...) at hand, by carrying pressure drop vs velocity measurement and fitting these coefficients. If the filter is anisotropic, the experiments should also be carried for various flow directions.

In principle it can also be predicted by a detailed two-phase analysis (where the solid is stationary), by sufficiently resolving the micro structure and calculating these coefficients from the results, but this may require a large model and some simplifying assumptions (e.g., assuming a simpler pore geometry, assuming wall roughness etc).

See, for example,
Barak Avisar, Lev Shemer, Abraham Kribus, Measurements of velocity fields in finite cylinder arrays with and without tip clearance, Experimental Thermal and Fluid Science, Volume 24, Issues 3–4, May 2001, Pages 157-167, ISSN 0894-1777, http://dx.doi.org/10.1016/S0894-1777(01)00048-6.where the resistance parameters of a pin array was measured (and some limited modeling was also applied).