Mixing in Heterogeneous Media Across Spatial and Temporal Scales: From Local Non-Equilibrium to Anomalous Chemical Transport and Dynamic Uncertainty

The MHetScale group investigates mixing, transport and reaction processes under heterogeneity from the pore to the field scale. Natural and engineered media are inherently heterogeneous, which gives rise to scale effects and process laws that can be very different from what is expected for homogeneous media. Heterogeneity increases the dispersion and thus global segregation of dissolved substances, while it enhances solute mixing locally, as illustrated in Figure 1. Heterogeneity induces a broad spectrum of mass transfer times, which leads to history-dependent transport and reaction dynamics. Our research focuses on the upscaling of transport, mixing and reaction phenomena from pore to Darcy to regional scale.


Figure 1: Concentration distribution in a steady heterogeneous flow (after Dentz and de Barros, J. Fluid. Mech., 2015). Flow heterogeneity enhances dispersion and thus segregation of a dissolved substance within a macroscopic support volume (blockscale). The concurrent creation of local concentration gradients enhances mixing.