Analysis of Suspended Sediment Transport in Open-Channel Flows: Kinetic-Model-Based Simulation

摘要

This paper presents a comprehensive analysis of suspended sediment transport in open channels under various flow conditions through a kinetic-model-based simulation. The kinetic model, accounting for both sediment-turbulence and sediment-sediment interactions, successfully represents experimentally observed diffusion and transport characteristics of suspended sediments with different densities and sizes. Without tuning any model coefficients, the nonmonotonic concentration distribution and the noticeable lag velocity with a negative value close to the wall are reasonably reproduced. Examination of flow conditions typical of suspension dominated rivers shows that the conventional method may overestimate or underestimate unit suspended-sediment discharge, depending on the Rouse number, sediment size, as well as shear velocity. The error may be less than 20% for d_p < 0.5 mm and might exceed 60% for d_p > 1.0 mm under typical flow conditions where shear velocity ranges from 1.0 to 12.5 cm/s and flow depth ranges from 1.0 to 5.0 m.