Effects of Concentration Fluctuations in Sediment Transport Process at Sediment-Laden gravity Currents

摘要

The present study investigates the effects of concentration fluctuations in sediment transport process at turbidity currents, experimentally. We have used the water sampling simple and acoustic Doppler Velocimeter (ADV) to get synchronous information about both instantaneous velocities and sediment concentration. Acoustic backscatter analyses were used for estimate the sediment concentration in sediment-laden flow. Various statistical measures of velocity and sediment concentration fluctuations and turbulent momentum and sediment fluxes are considered. Results show that the statistical moments of concentration fluctuation have a strong deviation from the normal distribution in concentration fluctuation. Vertical distribution of vertical and longitudinal concentration flux can be approximated by a near-Gaussian function. Finally, the settling velocity of sediment is measured with the experiment data that obtained with ADV.