Profile of Suspended Sediment Due to Wave Action

Abstract

A knowledge of sediment transport due to wave action is required to understand the dynamic process of nearshore morphology; however, these phenomena of sediment transport due to waves are complicated by the unsteady characteristics of the flow, the presence of turbulence and the interactions between the fluids and the sediment. These unsteady phenomena are much more complicated than those of steady uniform flows. Profiles of mean and unsteady concentrations are derived from the mass conservation equation using the diffusion coefficient profile adapted from the eddy viscosity profile, taking into account changes of the friction factor and boundary layer thickness in the presence of suspension. The theoretical profiles are expressed explicitly as functions of the friction factor, velocity and shear stress profile parameters, and the settling velocity of the sediment relative to the fluid velocity. The tabulated data available and the present experimental data of the mean concentration are used to fit the theoretical profile. The analysis shows that the friction factors in the presence of suspension decrease from the sediment‐free values in the same manner and magnitude as the von Karman constant.