非线性波输沙过程与挟沙能力研究

Study on sediment transport and carrying capacity under nonlinear waves

采用雷诺时均Navier-Stokes方程和标准k-ε湍流模型建立波浪水槽,并耦合泥沙输运模型构建波致悬沙输运模型。通过与实验数据的对比,显示此模型能够较好地模拟非线性波作用下泥沙浓度的时空分布。针对沙质泥沙,进一步分析了非线性波挟沙力随波参数的变化规律。分析结果表明,周期平均泥沙浓度的垂向分布随波高和周期的增加而增加,但随周期的增长速率逐渐减小。挟沙力随波高和波周期增加而增加,但随波周期增加的增幅逐渐减小;波周期内不同阶段的平均泥沙浓度随波高和周期的变化趋势与挟沙力相似,且速度峰值阶段的泥沙平均浓度高于速度谷值阶段。

A suspended sediment model coupled with numerical wave flume is built to simulate sediment transport under nonlinear waves by the Reynolds-averaged Navier-Stokes equations and the k-εturbulence model.The model can well reproduce the spatial and temporal distribution of sediment concentration carried by nonlinear wavesby comparing with experimental data.The variation of sediment carrying capacity is investigated.Results show that sediment carrying capacity increases with wave height and wave period as well,and the rate of the increase with wave period is slower than that with wave height.The averaged sediment concentration in different phase stages behaves similarly,and the averaged sediment concentration during the crest stages of velocity is higher than that of the tough stages.