Insight into particle detachment in clogging of porous media; a pore scale study using lattice Boltzmann method

摘要

Clogging of porous media is controlled by attachment of particles and their subsequent detachment. In this study, we explore particle transport at the pore scale by considering attachment and detachment processes. We use pore structures of three samples which have similar topological properties but different initial porosities. The main focus is on particle detachment, after they are attached to the solid grain boundaries, and to explore how particle detachment affects hydraulic properties and clogging of porous media. A new approach was proposed by combining the lattice Boltzmann method with a Lagrangian method to simulate fluid flow and particle transport, respectively. Comparisons between several simulations, with and without detachment, were used to evaluate the impact of particle detachment on fluid flow velocity distributions. The coefficients of Carman-Kozeny relation were used to relate porosity changes of each sample to its permeability alterations. Additionally, the influence of the initial porosity of the sample and flow velocity on the detachment process was analysed. The results show that compared to the impact of flow velocity, the initial porosity of the media has a greater influence on controlling the rate of detachment and change of pore structures.