A Unified General Resistance Formula for Uniform Coarse Porous Media

Abstract

Many authors studied the nonlinear relationship between seepage velocity and hydraulic gradient in coarse granular materials. They managed different approaches and variables to define the resistance formula applicable to that type of granular media. Based on the analysis of the different approaches and experimental data obtained by the corresponding authors, we propose a unified general seepage equation applicable to large-sized granular materials. Such an equation gives unity to the main nonlinear resistance formulas developed to date. Particularly relevant are the conclusions regarding the relationship of the linear (α*) and quadratic (β*) dimensionless coefficients of the resistance formula with the representative size of the particle and the geometrical features of the porous materials.