HR: 1340h
AN: H33H-1729    [Abstracts]
TI: Investigation of coupled heat and mass transfer in heterogeneous porous media using numerical simulations
AU: Illangasekare, T H
EM: tissa@mines.edu
AF: Environmental Science and Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, United States
AU: * Frippiat, C C
EM: cfrippia@mines.edu
AF: Environmental Science and Engineering, Colorado School of Mines, 1500 Illinois Street, Golden, CO 80401, United States
AU: * Frippiat, C C
EM: cfrippia@mines.edu
AF: Dept. of Civil and Environmental Engineering, Universite catholique de Louvain, Place du Levant, 1, Louvain-la-Neuve, B-1348, Belgium
AU: Zyvoloski, G A
EM: gaz@lanl.gov
AF: Earth and Environmental Sciences, Los Alamos National Laboratory, P.O. box 1663, Los Alamos, NM 87545, United States
AB: A significant body of knowledge exists on separates processes of thermal and mass transport in granular and fractured subsurface formations. However, the need to simulate these processes in a fully coupled way has become necessary to deal with problems associated with long-term-storage of nuclear waste, and the development of new technologies for subsurface remediation. Another emerging area for research is associated with the development of technologies for in situ extraction of underground resources. Numerical models that couple thermal and mass transport processes will play a crucial role in understanding the fundamental processes associated with these new technologies, as well as in making predictions on how complex subsurface systems are expected to behave. It is our hypothesis that heat transport will have a significant impact on distributions of solute concentration, through temperature-dependent dissolution and precipitation, and temperature-dependent rate-limited diffusive transfer of solutes in fractured or highly heterogeneous media. A number of issues related to the validity of existing numerical tools that capture these processes, and their application to field systems through up-scaling need to be investigated. With this overall goal in mind, in this preliminary study, we explore the effect of the variability of subsurface properties on heat and mass transport using simulations conducted using an existing multiphase model. The finite-element code FEHM (Finite-Element Heat and Mass transport code) used in this study was developed at Los Alamos National Laboratory. This code allows for the coupled simulation of flow, heat and mass transport, accounting for density effects and dissolution and/or precipitation reactions. Our analysis is based on two- and three-dimensional simulations using synthetic data sets. Heterogeneous facies distributions are generated according to Markov Chain transition probability models. A distributed source of constant temperature and concentration is located at the inlet model boundary, and the average concentration at the outlet boundary was evaluated. The results that investigated the influence of facies correlation lengths, hydraulic conductivity contrasts, and thermal conductivity contrasts are presented.
DE: 1829 Groundwater hydrology
DE: 1831 Groundwater quality
DE: 1832 Groundwater transport
DE: 1847 Modeling
DE: 1849 Numerical approximations and analysis
SC: Hydrology [H]
MN: 2007 Fall Meeting