The Incipient Motion Features of Sediment from Yangtze Estuary: Annular Flume Experiments

Huang Wei,Wan Yuan-Yang,Wu Hua-Lin,Wu Hua-Lin,Liu Ya-Kun

doi:10.1038/s41598-017-13651-2

Abstract

In this study, annular flume experiments are carried out, using the sediment samples collected from Yangtze estuary. The incipient velocity and the incipient shear stress of three different groups of median grain size of sediment are given. The turbulent kinetic energy method (TKE) is used to determine the bed shear stress (τ), by evaluating variations in the suspended sediment concentration (SSC) within the water column. The suspended sediment concentration increases with the increase of the bed shear stress. When the sediment concentration reaches a certain concentration, the rate of change in τ obviously slows down. As the concentration increasing again, the bed shear stress grows rapidly with different growth rate attributed to different grain size. The results of the experiments indicate that SSC and grain size have strong influence on τ.

Highlights

In this study, annular flume experiments are carried out, using the sediment samples collected from Yangtze estuary
When the bed shear stress increases to a certain level, the coarse sediment start moving and the suspended sediment concentration grows
The incipient velocity and critical shear stress can be known from the Fig. 3: V = 0.29 m/s, τcr = 0.19 Pa

Summary

Introduction

Annular flume experiments are carried out, using the sediment samples collected from Yangtze estuary. This paper gives the corresponding incipient velocities and the critical bed shear stresses for the different sediment size groups.

Results

Conclusion