PNNL

Abstract

Hybrid or multi-physics algorithms provide an efficient computational tool for combining micro- and macro-scale descriptions of a physical phenomenon. Their use becomes imperative when micro-scale descriptions are too computationally expensive to be conducted in the whole domain and macro-scale descriptions fail in a small portion of the computation domain. We present a hybrid algorithm to model a general class of reaction-diffusion processes in granular porous media, which includes mixing-induced mineral precipitation on or dissolution of the porous matrix that cannot be accurately described with a continuum (Darcy-scale) model. The pore-scale/Darcy-scale hybrid is constructed by coupling a solution of the reaction-diffusion equation (RDE) at the pore-scale with a continuum Darcy-level solution of theaveraged RDE. The resulting pore-Darcy scales hybrid is solved numerically by employing a multi-resolution meshless discretization based on Smoothed Particle Hydrodynamics (SPH) method, which ensures the seamless, non-iterative coupling of the two components of the hybrid. The presented computational examples illustrate the accuracy and efficiency of the proposed hybrid model.