Velocity Profiles of Turbulent Sediment-laden Flows in Open-channels

In this paper, we carried out a study of the velocity profile of sediment-laden flows in open channels using the two-phase mixture model for two-phase flows. Based on the two-fluid model of solid-liquid two-phase flows, the governing equations for water-sediment mixtures were derived. The drift velocity, a key variable involved in the two-phase mixture equations, is derived from the momentum conservation equation for solid phase. It shows that inertia of flow, particulate turbulence, and collisions effect contributes to the dispersion of the sediment particles in turbulent flows. Using the two-phase mixture equation, the vertical velocity profile of open channel flows is obtained. Further analysis implies that the vertical distribution of the velocity of water-sediment mixture is considerably affected by multiple agents including collisions between particles, density stratification, and turbulence of particles. Comparisons of present studies with experimental observations from a wide range of experiments are presented which show that present study is in good agreement with experiments.