| Fluid flow in a porous medium is a common phenomenon in nature, and is encountered in various disciplines, e.g., civil engineering, chemical engineering, reservoir engineering, agricultural engineering, prevention of subsoil water pollution, and complicated fluid flow in biont, and other related topics. So a betterunderstanding of fluid flow in a porous medium is of great significance. In general, flows in porous media are treated theoretically at various scales: microscopic scale (pore), macroscopic scale (laboratory, local), and domain scale. The macroscopic scale is defined as a representative element, which is much larger than the microscopic scale but much smaller than the domain scale. In many situations, two or multiple scale coexist. As the porous structure of the medium is very complex and the governing equation is nonlinear, some of the flow properties are difficulty to determine accurately with experimental techniques and theoretical method. Improvement of computers and the subsequent development of methods of computational fluid dynamics (CFD) have gradually made it possible to directly solve many complex fluid-dynamical problems. Though CFD can provide accurate results for flows in porous media, they are not convenient because of grid accuracy and boundary stability.The dynamics of fluid flows are generated at the microscopic level and could be, inprinciple, modeled with direct molecular-dynamics simulations. Obviously, in practice it is unreasonable to slove real flow systems. Flows in a porous medium can also be modeled with simplified (more macroscopic) models, just as many other dynamics systems. One of such simplified approaches is lattice Boltzmann method (LBM), which derived from lattice gas automata, has been proposed as an efficient numerical tool to investigate fluid dynamics and dispersion problems with highly complex geometries, such as porous media. The LBM allows a detailed discretization of the porous geometry and hence one can have an exact simulation of...
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