Computational Investigation On The Electrical And Transport Properties Of Porous Media Model

Electrical properties and transport properties are two important properties of porous media,as they are widely used in various disciplines such as geophysical surveying,remote sensing,petroleum exploration,medicine,materials science,and non-destructive testing.Based on a sufficient investigation of relevant theoretical knowledge,a numerical computation using the Finite Element Method(FEM)is carried out on different porous models to discuss the electrical and transport properties.As the first part of this thesis,the electrical properties of two-component porous models with different geometries are studied based on the effective media theory.Using the electromagnetic wave excitation and periodic boundary conditions,the effective dielectric constant of each model is numerically computed and compared with the analytic results obtained by several mixing-law formulas.The effective dielectric constant variation behaviors responding to seven kinds of geometrical variation such as pore size,porosity,pore shape,pore distance,pore distribution etc.are investigated and summarized.As the second part,the transport properties of a two-component porous model with different porosities are investigated.The motivation of this study is to find out a quantitative relationship between the electrical and the hydraulic tortuosities which has not been thoroughly discussed or clearly concluded during the past.The current density streamlines and velocity streamlines are obtained respectively by numerical simulation conducted in the laminar physics field and current physics field environments.The tortuosity is obtained respectively by computing the streamline length and applying the vector average method proposed by Duda to validate each other.Finally,the simulation results are compared with the logarithmic function model,the power law model,and the Archie's model with fitting parameters applied and four analytic formulas are revised.