Pore-Scale Study of the Collector Efficiency of Nanoparticles in Packings of Nonspherical Collectors

摘要

Pore-scale simulations of flow and transport through a filter were used to predict clean-bed filtration of nano-particles from a 3D image of the filter. X-ray micro-computed tomography was used to obtain the geometry and topology of the filter consisting of flattened half-spherical collectors. A Lattice-Boltzmann method was used to model fluid flow and particle transport in the volumetric image of the filter. Nano-particles are considered that are so small that diffusion, as compared to the processes of gravitational settlement and interception, dominates particle deposition. A correlation equation is determined for the average collector efficiency for diffusion through regression analysis performed for a set of numerical breakthrough experiments for a range of suspended particle sizes and Darcy velocities. This correlation quantifies the collector size by the surface average equivalent sphere diameter. The newly derived correlation agrees well with experimental data.