Cohesive Sediment Transport Calculation And Analysis In Seashore

At present, two primary methods are used to deal with the source/sink term in advective and dispersive transport equation of suspended sediment when studying on estuary and coastal sediment movement. One is the flow scouring force method in domestic research, and the other is the bottom shearing method in the Occident. The two means are different in physical meanings, although both are used to solve the same problem. This paper discusses how to use bottom shearing stress method to determine the resuspension rate and deposition rate, and how to select and calculate the correlative parameter.Based on the analysis of characteristics of estuary and coastal hydrodynamic and of sediment motion, paper takes into account the influence of the consolidating in erosion algorithm. According to the dry density, sediment on the bed can be divided into two parts, the new deposits and settled bed. The resuspension rate of the two kinds sediment shows different relationship for the excess shear stress. Thus, the paper adopts the different formulas to solve them. In addition, at deposition algorithm, the paper takes into account the sediment concentration and excess shear stress adequately.When defining the settling velocity, the discourse concludes the certain relation between sediment diameter and fall velocity, then educes two formulas to define the parameter for the cohesionless sediment and cohesive sediment, respectively. Moreover, it sums up some ways to define some other parameters in the paper, i.e. roughness coefficient, turbulent exchange coefficients and the correlative parameters during the erosion algorithm and deposition algorithm.It applies these methods into laboratory flume experiment, tidal flow and sediment transport in JiaoZhou Bay nearby and Yemen waterway in the paper. These research findings have both theoretical and applicable value of estuary and coastal sediment movement.