A multiscale study of density-driven flow with dissolution in porous media. (August 2020)

• Record Type: Journal Article
• Authors: Meng, Xuhui; Sun, Haoran; Guo, Zhaoli; Yang, Xiaofan
• Is Part Of: Advances in water resources. Volume 142(2020)
• Publication Date: 2020-08
• Subjects: Reactive transport -- Density-driven flow -- Chemical dissolution -- Linear stability analysis -- Pore-scale modeling -- Lattice Boltzmann method; Hydrology -- Periodicals; Hydrodynamics -- Periodicals; Hydraulic engineering -- Periodicals; 551.48
• DOI: 10.1016/j.advwatres.2020.103640
• Languages: English
• ISSNs: 0309-1708

Abstract

Highlights: Numerical simulations with linear stability analysis are conducted to study density-driven flow with dissolution in porous media. A multiscale approach that combines Darcy-scale linear stability analysis and pore-scale simulations are performed. The transport processes are largely dominated by the interplay among density contrast, reaction rate and porosity evolution. Abstract: In the present work, a suite of numerical experiments with linear stability analysis are conducted to study density-driven flow with chemical dissolution of two reactive fluids in synthetic porous media. Linear stability analysis at the Darcy scale is first performed to predict the interfacial phenomena and instability at the initial time. Pore-scale simulations using the lattice Boltzmann method (LBM) are further conducted to capture more mechanistic information and advance the understanding of the transport processes. Under different scenarios, it is demonstrated that the transport processes exhibit distinct behaviors, which are largely dominated by the interplay among density contrast, chemical reaction rate and evolution of the porosity/permeability. All the results indicate that the interfacial instability can be triggered by the density contrast between two miscible fluids, leading to the Rayleigh-Taylor (R-T) instability. The R-T instability can be suppressed by the heterogeneous surface reaction between the fluid and solid phases, which prevents the transport of the denser fluid. Over the long term, it is found that the interfacial instability is influenced by the evolution of the porosity/permeability due to dissolution, which potentially restarts the transport of the denser fluid.