HR: 1340h
AN: H33H-1727    [Abstracts]
TI: Random-walk Particle Tracking for Transport Simulation: Extension to Multi-Component Reactions.
AU: * Scheibe, T D
EM: tim.scheibe@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99354, United States
AU: Fang, Y
EM: yilin.fang@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99354, United States
AU: Tartakovsky, A M
EM: alexandre.tartakovsky@pnl.gov
AF: Pacific Northwest National Laboratory, PO Box 999 MS K9-36, Richland, WA 99354, 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
AB: Random-walk particle tracking methods have been used extensively to simulate transport of conservative solutes in groundwater systems, and are particularly advantageous in cases of heterogeneous flow and advection- dominated transport. However, such models have not been broadly applied to reactive transport simulations, mostly because reactions are formulated in terms of concentrations and conversion back and forth between particle density and concentration leads to inefficiencies and numerical errors. We present an extension of particle tracking methods to include multiple mobile reacting species, in which reactions are formulated in terms of state transition probabilities rather than rates of change of concentration. This approach has previously been successfully applied to cases where there is only one mobile reactant (e.g., sorption/desorption or radioactive decay reactions), but not to multiple interacting mobile species. This particle-tracking method is particularly well- suited to simulation of reactive transport scenarios in which concentrations are poorly-defined because of strong concentration gradients at scales smaller than the REV. As an illustrative example, we apply our approach to an intermediate-scale experiment conducted in a quasi-two-dimensional flow cell in which calcium carbonate precipitation occurs along a narrow interface between two solutions.
DE: 1805 Computational hydrology
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
SC: Hydrology [H]
MN: 2007 Fall Meeting