HR: 11:50h
AN: H42A-07    [Abstracts]
TI: Pore-Scale Smoothed Particle Hydrodynamics Model for Reactive Transport and Mineral Precipitation.
AU: * Tartakovsky, A M
EM: alexandre.tartakovsky@pnl.gov
AF: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 United States
AU: Meakin, P
EM: Paul.Meakin@inl.gov
AF: Idaho National Laboratory, P.O. Box 1625, MS 2025, Idaho Falls, ID 83415 United States
AU: Scheibe, T D
EM: tim.scheibe@pnl.gov
AF: Pacific Northwest National Laboratory, P.O. Box 999, Richland, WA 99352 United States
AB: A numerical model based on smoothed particle hydrodynamics (SPH) was developed and used to simulate reactive transport and mineral precipitation in porous and fractured porous media. Reliable and broadly applicable computer models for micro-scale flow and transport in porous media are needed to develop a better understanding of a wide range of natural and commercially important processes. Because of the difficulties associated with geometrically complex pore-scale boundaries that are dynamically changing as a result of precipitation and the non-linearity of the flow and reactive transport equations, traditional grid-based methods have not been successfully applied to these pore-scale processes. An alternative approach is to use mesh-free methods such as SPH. Because of its Lagrangian particle nature, SPH has several advantages for modeling pore-scale flow and reactive transport: i) in a Lagrangian framework there is no non-linear term in the momentum conservation equation, so that SPH allows accurate solution of momentum dominated flows; ii) complicated physical and chemical processes associated with realistic equations of state, changes in solid boundaries due to dissolution or precipitation and chemical reactions are easy to simulate. An SPH model was used to study the effects of porosity, pore scale heterogeneity, Damkohler numbers and Peclet numbers on reactive transport and to estimate effective reaction coefficients and mass transfer coefficients. The changes in porosity, conductivity and transport parameters resulting from mineral precipitation were also investigated. Hysteresis in the reaction rate coefficient and mass transport coefficient resulting from changing porosities, mass fluxes and reactive surface areas was observed. Flow and transport with low Damkohler numbers and high Peclet numbers was found to result in uniform precipitation. When the Damkohler number was high and the Peclet number was low, precipitation occurred mainly around the supersaturated solution injection areas.
DE: 1829 Groundwater hydrology
DE: 1839 Hydrologic scaling
DE: 1847 Modeling
DE: 3225 Numerical approximations and analysis (4260)
DE: 3610 Geochemical modeling (1009, 8410)
SC: Hydrology [H]
MN: Fall Meeting 2005