화학공학소재연구정보센터
Journal of Colloid and Interface Science, Vol.298, No.1, 183-191, 2006
Porous agglomerates in the general linear flow field
We calculate the flow within and around a porous spherical agglomerate Suspended in the general linear flow field, and also the flow induced by its rotation, We use the Stokes equations exterior to the particle and the Brinkman equations inside it. The effect of particle permeability oil the flow is expressed via the Brinkman parameter beta = r(0)/root k where r(0) is particle radius and k is its permeability. With translational creeping motion of porous spheres in a quiet fluid investigated by Debye and Bueche [P. Debye, A.M. Bueche, J. Chem. Phys. 16 (6) (1943) 573-579], this study provides information necessary for investigating dynamics of porous particles moving in creeping shear flows under the action of external forces and torques. The agglomerate flow field solutions are used to calculate the effective viscosity of a dilute Suspension of porous solid aggregates, which generalizes the well-known Einstein's equation for solid suspensions. The agglomerate effective viscosity diameter is proposed which allows using the Einstein's formula evaluation of the agglomerates suspension viscosity. (c) 2005 Elsevier Inc. All rights reserved.