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Titolo: STEADY INCOMPRESSIBLE LAMINARFLOW IN POROUSMEDIA
Autore: LIU SJ; AFACAN A; MASLIYAH J;
 Indirizzi:
 UNIV ALBERTA,DEPT CHEM ENGN EDMONTON T6G 2G6 AB CANADA UNIV ALBERTA,DEPT CHEM ENGN EDMONTON T6G 2G6 AB CANADA
 Titolo Testata:
 Chemical Engineering Science
fascicolo: 21,
volume: 49,
anno: 1994,
pagine: 3565  3586
 SICI:
 00092509(1994)49:21<3565:SILIP>2.0.ZU;22
 Fonte:
 ISI
 Lingua:
 ENG
 Soggetto:
 CONTINUUM APPROACH; PRESSUREDROP; PACKEDBEDS; SPHERES; RESISTANCE; PIPES;
 Tipo documento:
 Article
 Natura:
 Periodico
 Settore Disciplinare:
 Science Citation Index Expanded
 Citazioni:
 44
 Recensione:
 Indirizzi per estratti:



 Citazione:
 S.J. Liu et al., "STEADY INCOMPRESSIBLE LAMINARFLOW IN POROUSMEDIA", Chemical Engineering Science, 49(21), 1994, pp. 35653586
Abstract
Steady incompressible laminar flow in porous media is studied. The volume averaging technique is revisited resulting in a new averaging approach to the pressure gradient term. The difference between the traditionally obtained volume averaged equation for very small flow rate andBrinkman's equation is resolved. The KozenyCarman theory is modified. By including a twodimensionally modelled tortuosity and curvature ratio as well as pore crosssectional area variation, a new semiempirical equation for the pressure drop for flow through porous media is obtained. The pressure drop dependence on the porosity epsilon for Darcy's flow region is established as epsilon(11/13)(1  epsilon)(2) as opposed to epsilon(3)(1 ,)2 in the original KozenyCarman's theory. A modified Reynolds number is also defined. The regions of Darcy's flow and Forchheimer's flow are unified. The wall effects are incorporated into the unified pressure drop equation. The final form of the normalized pressure drop equation for a onedimensional medium is given by Delta p'/L d'(2)(s) epsilon(11/3)/mu U(1  epsilon)(2) = f(v) = 85.2[1 pi d(s)/6(1  epsilon)](2) + 0.69[1  pi(2)d(s)/24(10.5d(s))]Rem Rem(2)/16(2) + Rem(2) for d(s) = d'(s)/D < 0.75. Here f(v) is the normalized pressure drop factor, Delta p' is the pressure across a fixedthickness L of the porous bed, epsilon is the porosity, d: is the equivalent spherical particle diameter, D is the bed diameter, U is the superficial velocity or fluid discharge rate, mu is the dynamic viscosity of the fluid and Rem is the modified Reynolds number. The onedimensional pressure drop equation is also modified to give a shear factorfor use with the volume averaged NavierStokes equation and it is given as F = (1  epsilon)(2)/4 epsilon(11/3)d(s)(2){85.2[1 + pi d(s)/6(1 epsilon)](2) + 0.69[1  pi(2)d(s)/24(1  0.5d(s))]Rev Rev(2)/16(2) + Rev(2)} where F is the shear factor and Rev is the local modified Reynolds number. The semitheoretical model was tested with available acid new experimental pressure drop data for packed beds. Further comparison was made with experimental pressure drop data for flow in a fibrous mat. The model was found to correlate well for the whole range of Reynolds number, wall effects and porosity studied.
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Documento generato il 05/12/20 alle ore 01:46:53