Investigation on reactive flow through porous media by quadtree Lattice Boltzmann

Abstract

In this study, in order to investigate the effect of the underlying pore-scale processes on continuum scale simulations of porous media dissolution, we improve the standard Lattice Boltzmann method using Quadtree grid refinement approach to simulate fluid flow and reactive transport through large domain sizes. Our results have shown considerable computational improvements up to 80% in simulation time together with increased numerical accuracy. The results and the added value of the new approach are discussed using comparison of our model with the conventional LBM. Moreover, we have applied a systematic analysis by increasing complexity levels and starting from fluid flow and continuing with tracer transport and reactive transport in single pores, and ultimately, reactive transport in dissolving porous structures. For each case, the accuracy and computational benefits of the Quadtree models are discussed and dimensionless numbers are used to characterize regimes of flow and reaction in each step of comparison. Porosity-permeability variation in a 2D pore structure and mass transfer coefficient in a closed-end fracture with porous walls are then evaluated under different flow conditions.