Research On Some Flow Properties Of Fluid In Porous Media

Porous media exist everywhere in nature such as engineering materials, organs, oil and water reservoirs etc. Due to the structural complexity of porous media, the studies of flow behavior for fluid flow in porous media have steadily received much attention. First, we briefly introduce the concepts about porous media and fractal, and summarize the theory basis of fractal geometry.In chapter 2, we focus on derivation of the tortuosity models for flow of Newtonian incompressible fluid in two- and three-dimensional porous media with spherical, cubic and plate-like particles by applying the geometrical method. We first present the ideal geometrical models of porous media to show the ideal and representative streamlines based on the assumption that some particles in porous media are unrestrictedly overlapped and hence of different configurations, then the average tortuosity is derived by geometrically and weightedly averaging these representative flow paths. The model predictions agree well with the available correlations obtained numerically and experimentally, they are expressed as a function of porosity with no empirical constant, and they are helpful for understanding the physical mechanism for tortuosity of flow paths in porous media.In chapter 3, the power-law and Bingham fluid flow in porous media are studied. Based on the assumption that the porous medium consists of a bundle/set of tortuous streamlines/capillaries and on the fractal characteristics of pore size distribution in porous media, we develop the fractal expressions for flow rate, hydraulic conductivity and apparent viscosity for Power-law fluid flow in a single capillary, we develop the fractal expressions for flow rate, velocity, apparent viscosity and effective permeability for Power-law fluid flow in porous media, and develop the fractal expressions for flow rate, velocity and starting pressure gradient for Bingham fluid flow in porous media. The present models relate non-Newtonian fluids to the structural parameters of prous media, then the physical mechanism for non-Newtonian fluid flow in porous media is well understood.In chapter 4, the plane-radial and plane-parallel flows for Newtonian fluid in fractal porous media are analyzed. Based on the same assumption as that in chapter 3, the expressions for porosity, flow rate, velocity and permeability for both radial and parallel flows are developed. The proposed expressions are expressed as a function of tortuosity, fractal dimension, maximum and minimum pore diameters, and there are no empirical constant and every parameter has clear physical meaning in the proposed expressions. The pressure distribution equations for slightly compressible fluid flow in fractal porous media for the plane-radial and plane-parallel flows are presented, and they are found to be formally the same as those obtained by the conventional method.Finally, some possible research directions for future study are suggested regarding the other transport parameters in porous media.