Department of Chemical & Biomolecular Engineering, National University of Singapore, 117576 Singapore.
J Chem Phys. 2011 Jul 7;135(1):014904. doi: 10.1063/1.3606394.
Hydrodynamic resistance to particle transport arising from the solid mass in porous media is of fundamental importance. We investigate an axisymmetric creeping flow caused by a spherical particle migrating in a spherical cavity or connected cavities of equal size by a boundary element method. Each cavity has either one or two circular apertures, through which a sufficiently small particle can pass. Drag force on the particle is calculated to determine the correction factor to the Stokes law. It is found that when passing through an aperture, the particle experiences a local maximum drag force larger than that located in the cavity center. This force is also greater than that for the particle near the closed end at the same smallest surface-to-surface distance. For connected cavities open to the exterior fluid, the drag force is smaller than that in the corresponding closed system.
多孔介质中固体质量引起的颗粒输运的流体动力阻力至关重要。我们采用边界元法研究了球形颗粒在球形腔或等大小连通腔中迁移引起的轴对称蠕动流。每个腔有一个或两个圆形孔，足够小的颗粒可以通过这些孔。计算颗粒上的阻力以确定对 Stokes 定律的修正因子。结果发现，当颗粒通过孔时，它会经历一个大于腔中心的局部最大阻力。该力也大于具有相同最小表面-表面距离的封闭端附近的颗粒的阻力。对于与外部流体连通的连通腔，阻力小于相应的封闭系统。
