HR: 1340h
AN: H33H-1730    [Abstracts]
TI: Lattice Boltzmann Method for Heterogeneous and Anisotropic Advection-Dispersion Equation in Porous Medium Flow
AU: * Servan-Camas, B
EM: bserva1@lsu.edu
AF: Louisiana State University, Department of Civil and Environmental Engineering, 3418G Patrick F. Taylor Hall, Baton Rouge, LA 70803,
AU: Tsai, F T
EM: ftsai@lsu.edu
AF: Louisiana State University, Department of Civil and Environmental Engineering, 3418G Patrick F. Taylor Hall, Baton Rouge, LA 70803,
AB: The objective of this study is to solve the heterogeneous, anisotropic advection-dispersion equation (ADE) in porous media using lattice Boltzmann method (LBM). The recovery of anisotropic hydrodynamic dispersion using LBM has not been extensively studied, and using LBM to solve the ADE remains a challenge. In this work, we develop a multidirectional-speed-of-sound (MDSS) method, which are direction-dependent, to directly link the second moment of equilibrium distribution functions (EDFs) with different components in the dispersion tensor. Using MDSS and second-order EDFs, we recovered the ADE with additional numerical diffusion terms, which are not negligible in the general case. We introduced pseudo-velocities to reduce the numerical diffusion terms one order lower and keep the LBM results at second-order accuracy. Two-dimensional mass instantaneous release problems in uniform flow are solved to demonstrate the capability of using MDSS to recover the anisotropic hydrodynamic dispersion. Good agreement is found between the analytical and LBM solutions for high ratio of longitudinal to transverse dispersivities.
DE: 1829 Groundwater hydrology
DE: 1832 Groundwater transport
DE: 1847 Modeling
DE: 1849 Numerical approximations and analysis
SC: Hydrology [H]
MN: 2007 Fall Meeting