HR: 10:35h
AN: H32D-02 INVITED    [Abstracts]
TI: Hybrid Pore- and Darcy-Scale Models of Coupled Reactive Transport.
AU: * Scheibe, T D
EM: tim.scheibe@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99352, United States
AU: Tartakovsky, A M
EM: alexandre.tartakovsky@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99352, United States
AU: Fang, Y
EM: yilin.fang@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99352, United States
AU: Richmond, M C
EM: marshall.richmond@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99352, United States
AU: Rakowski, C L
EM: cindy.rakowski@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99352, United States
AU: Wood, B D
EM: brian.wood@oregonstate.edu
AF: Oregon State University, School of Chemical, Biological and Environmental Engineering, Corvallis, OR 97331, United States
AU: Tartakovsky, D M
EM: dmt@ucsd.edu
AF: University of California San Diego, Department of Mechanical and Aerospace Engineering, La Jolla, CA 92093, United States
AU: Battiato, I
EM: ibattiat@ucsd.edu
AF: University of California San Diego, Department of Mechanical and Aerospace Engineering, La Jolla, CA 92093, United States
AU: Redden, G D
EM: george.redden@inl.gov
AF: Idaho National Laboratory, PO Box 1625 MX 2208, Idaho Falls, ID 83404, United States
AU: Palmer, B J
EM: bruce.palmer@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99352, United States
AB: Pore-scale simulations of flow, transport, and reactions in porous media (in which the geometry of solid grains and pore spaces is explicitly quantified) are being used to demonstrate links between microscopic and macroscopic phenomena. A diverse set of simulation methods have been developed including pore network models, Lattice-Boltzmann models, finite-volume PDE solvers, and Smoothed Particle Hydrodynamics (SPH). Typically, pore-scale models are used to develop understanding of fundamental processes that can then be incorporated into larger-scale models (e.g., darcy-scale) that treat porous media as effective continua. Rigorous upscaling requires that specific conditions or assumptions be met that are often, but not always, valid. In particular, where conditions that govern macroscopic processes are highly localized (such as strong concentration gradients at the scale of individual pores), valid means of upscaling pore-scale processes may not exist. An alternative to upscaling in such situations is hybrid multiscale modeling, in which multiple models defined at fundamentally different length and time scales are combined within the same overall spatial and temporal domain. Hybrid multiscale simulations are motivated by problems in which large-scale phenomena of interest (e.g., flow and contaminant transport) are strongly influenced by processes occurring at much smaller scales (e.g., diffusive mixing and reactions) that are not well represented by effective or averaged processes or properties. Executing an exhaustive simulation of processes at the smallest scales for a domain of engineering significance is currently impractical, and likely to remain so for a very long time. However, the hybrid multiscale approach, in which a small-scale model with high resolution is utilized in a fraction of the overall domain and is linked to a large-scale model with coarse resolution over the remainder of the overall domain, can provide necessary efficiency of characterization and computation that will render solution of these problems practical. We will present a number of specific pore-scale simulations based on the SPH method and a high-resolution finite volume method. We will then review hybrid multiscale modeling techniques and illustrate the hybrid approach using two different hybrid approaches to a diffusion-reaction problem.
UR: http://subsurface.pnl.gov
DE: 1805 Computational hydrology
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1847 Modeling
SC: Hydrology [H]
MN: 2007 Fall Meeting