Numerical simulation method for reactive solute transport based on micro-continuum medium model

Abstract

Significance Fluid-solid interactions in reactive solute transport processes, governed by physical and chemical heterogeneities, dictate the evolution of subsurface geomaterials, resulting in nonlinear behaviours and multiscale features. It has become increasingly evident that examining the feedback between microscopic features and macroscopic behaviours in geomaterials is critical in various academic and industrial applications. Progress In this study, we introduce the concept and framework, mathematical and numerical models of the micro-continuum medium, as well as multiscale solvers and applications. Challenges in co-designed simulations and experiments are also discussed. Conclusion and Prospects Despite offering valuable insights into reactive transport processes, continuum-scale modelling or pore-scale modelling suffers from a gap between theoretical understanding and computational prediction. Recently, an alternative conceptualization of the multiscale problem involves the implementation of the Darcy-Brinkman-Stokes (DBS) equation in a single micro-continuum domain to identify reactive transport patterns across spatial scales under changing flow regimes. As fluid-solid interfaces cannot be explicitly resolved as in pore-scale models, the micro-continuum medium approach has the advantage of accommodating complex geometries or evolving interfaces without increasing computational costs.

Keywords

• reactive solute transport
• micro-continuum medium approach
• multiscale numerical simulation
• mechanistic understanding