Impact of spatially correlated pore-scale heterogeneity on drying porous media

TL;DR

This study investigates how spatially correlated pore-scale heterogeneity influences drying in porous media, combining modeling and experiments to reveal that larger correlation lengths enhance drying rates by promoting preferential pore drying.

Contribution

It introduces a combined pore-scale model and microfluidic experiments to quantitatively analyze the impact of heterogeneity correlation length on drying behavior.

Findings

Larger correlation lengths promote preferential drying of large pore clusters.

Increased correlation length prolongs liquid connectivity and surface wetness.

Model predictions align well with experimental results despite manufacturing uncertainties.

Abstract

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.