  We study the effect of spatially-correlated heterogeneity on isothermal
drying of porous media. We combine a minimal pore-scale model with microfluidic
experiments with the same pore geometry. Our simulated drying behavior compare
favorably with experiments, considering the large sensitivity of the emergent
behavior to the uncertainty associated with even small manufacturing errors. We
show that increasing the correlation length in particle sizes promotes
preferential drying of clusters of large pores, prolonging liquid connectivity
and surface wetness and thus higher drying rates for longer periods. Our
findings improve our quantitative understanding of how pore-scale heterogeneity
impacts drying, which plays a role in a wide range of processes ranging from
fuel cells to curing of paints and cements to global budgets of energy, water
and solutes in soils.
