A model for particle deposition and filter cake buildup in granular media.

摘要

The objective of this work is to develop a general technique for a better quantitative understanding of particle deposition that can be applied for studying particle deposition under as few assumptions, regarding the nature of the deposition i.e. external or internal deposition, as possible. A major objective of this study is to also include the effect of long range hydrodynamic interactions on particle deposition. The optimum form of the mobility tensors for hydrodynamic interactions was identified. The Stokesian Dynamics approach was used as a basis for constructing a model for particle deposition in granular media. A model was developed for the study of particle deposition on a granular medium. A separate model for studying 'deep bed' deposition within a granular medium was constructed by using the Ewald summation method for unequal sized particles. The results from these models indicate that the particle size and the structure of the granular medium play a very important role in particle capture and bridging. The 'deep bed' filtration model showed reasonable agreement with experimental data. Additional work needs to be done to incorporate multibody interactions and higher order multipoles into this model. The use of a simpler lattice based model was also investigated. Results from this model indicate that the size of the particle relative to the grain size is one of the most important parameters for particle bridging. The model also showed reasonable agreement with experimental data.