A Closer Look: High-Resolution Pore-Scale Simulations of Solute Transport and Mixing Through Porous Media Columns

Mixing is pivotal to conservative and reactive transport behaviors in porous media. Methods for investigating mixing processes include mathematical models, laboratory experiments numerical simulations. The latter have been historically limited by the extreme computational resources needed solving flow at microscopic scale within complex pore structure of a three-dimensional medium, while dealing with sufficiently large domain order generate meaningful emergent continuum-scale observables. We present results such set virtual column experiments, which conducted taking advantage modern high-performance computing infrastructure Computational Fluid Dynamics software capable massively parallel approach has important advantages as full control over experimental conditions well high spatial temporal resolution measurements. Hydrodynamic dispersion agree empirical theoretical literature link dispersivity median grain size, elucidating impact size variability on critical Péclet number. Reactive also indicate that relative degree incomplete related granular material’s mean hydraulic radius not directly size. When compared well-known experiment similar configuration, less observed our offer partial explanation this discrepancy, showing how an apparent nonlinear absorbance–concentration relationship may induce measurement error presence local concentration fluctuations.