(383e) Upscaling of Pore-Scale Simulations

Dissolution by subsurface flows is a critical component in the development of karst systems, which transport much of the water we consume. Modeling subsurface flow and reactant transport on large (km) scales necessarily involves statistical descriptions of the underlying pore space. We use finite-volume simulations, based on the OpenFOAM toolkit, to investigate the fundamentals of dissolution in simple well-controlled models of a porous material. Our goal is to develop an upscaling for transport limited dissolution, using the pore-scale simulations for guidance.

I will first present a validation of the physical model, by comparing simulations of a dissolving cylinder with the results of a microfluidic experiment and a conformal mapping simulation. Then I will describe ongoing work, which uses insights drawn from simulations of arrays of disks to suggest ways of upscaling in cases where dissolution is predominantly transport controlled. Numerical simulations show that a multiplicative decomposition is in good agreement with simulations. The final step is a distance-dependent rescaling of the time, which allows different REV's (Representative Element Volume) in the array to be mapped to the dissolution of a single REV.

This work was supported by the U.S. Department of Energy, Office of Science, Office of Basic Energy Sciences, Chemical Sciences, Geosciences, and Biosciences Division under Award Number DE-SC0018676, and by the National Science Center (Poland) under research Grant No. 2012/07/E/ST3/01734