HR: 0800h
AN: H11D-1295    [Abstracts]
TI: Pore-scale Simulation of Entrapped Nonaqueous Phase Liquid Dissolution Using a Coupled Lattice Boltzmann-Finite Volume Modeling Approach
AU: Pan, C
EM: dpan@email.unc.edu
AF: Center for Integrated Study of the Environment, Department of Environmental Sciences and Engineering, University of North Carolina, CB 7400, 104 Rosenau Hall, Chapel Hill, NC 27599-7400 United States
AU: Dalla, E
EM: elisa.dalla@unimib.it
AF: Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, Milano, 20126 Italy
AU: Franzosi, D
EM: davidefr@email.it
AF: Department of Environmental Sciences, University of Milano-Bicocca, Piazza della Scienza 1, Milano, 20126 Italy
AU: * Miller, C T
EM: casey_miller@unc.edu
AF: Center for Integrated Study of the Environment, Department of Environmental Sciences and Engineering, University of North Carolina, CB 7400, 104 Rosenau Hall, Chapel Hill, NC 27599-7400 United States
AB: For nonaqueous phase liquids (NAPLs) that are commonly found in contaminated groundwater environments, interphase mass transfer between the NAPL phase and the aqueous phase is a process of crucial importance for both accurate assessment of risk and the design of cost-effective techniques for remediation. The NAPL-aqueous phase mass transfer process has been studied extensively using macroscale laboratory experiments. However, these experiments alone do not provide a complete characterization of factors that affect the rate at which this process proceeds and they do no provide a means to connect to microscale processes that influence the observed macroscale behavior. We apply a pore-scale modeling approach to simulate the dissolution of a residual NAPL in a three-dimensional random sphere-pack medium. We generate residual NAPL distributions using a morphological approach and quantitatively characterize the entrapped nonwetting phase by calculating volume, orientation, interfacial area, and shape of isolated NAPL regions. We use a multiple-relaxation time lattice-Boltzmann approach to obtain a detailed aqueous phase flow field, then solved the advective-diffusive equation in the pore space using a high-resolution, adaptive-stencil finite-volume scheme and an operator splitting algorithm. The accuracy of the model is verified by comparison with three-dimensional benchmark problems. We show a good agreement between the mass transfer rates predicted in the computational approach and previously published experimental observations. Predicted results of the Sherwood number as a function of the Reynolds number (Re), Schmidt number (Sc), and NAPL saturation are compared to correlations developed by several investigators.
DE: 1805 Computational hydrology
DE: 1829 Groundwater hydrology
DE: 1849 Numerical approximations and analysis
SC: Hydrology [H]
MN: Fall Meeting 2005