Application of Ergun Equation to Computation of Critical Shear Velocity Subject to Seepage

The Ergun equation that is widely used in chemical engineering is generalized for describing seepage through the sediment boundaries in this study. Comparisons with the measurements of the hydraulic gradient for flows through packed beds show that the Ergun equation may not be suitable for the transitional zone where both viscous and inertial effects are of the same order of magnitude. The generalized Ergun equation is then used to evaluate the critical shear velocity for incipient sediment motion subject to seepage. The computed results are finally compared to the experimental data and those predicted using the previously proposed approach.