| 波流边界层水沙运动数值模拟——Ⅲ.底部高含沙层模拟 |
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| 引用本文： | 左利钦,陆永军,朱昊.波流边界层水沙运动数值模拟——Ⅲ.底部高含沙层模拟[J].水科学进展,2019,30(6):810-822. |
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| 作者姓名： | 左利钦 陆永军 朱昊 |
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| 作者单位： | 南京水利科学研究院水文水资源与水利工程科学国家重点实验室, 江苏南京 210029 |
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| 基金项目： | 国家重点研发计划资助项目（2017YFC0405900）；国家自然科学基金资助项目（51520105014） |
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| 摘 要： | 为了解析底部高含沙层特征，研究了物理影响机制和时均含沙量剖面。采用波流边界层1DV泥沙数学模型，结合试验资料，通过设置不同的计算工况进行了影响因素敏感性分析；在此基础上，提出波浪相关的时均泥沙扩散系数分布，考虑主要影响机制，推导了基于边界层物理过程的波浪作用下时均含沙量剖面表达式。结果表明，底部高含沙层与波浪边界层密切相关，是受水动力和床面形态综合影响的结果。仅建立高含沙层与水动力或床面形态的单一关系是有局限性的。含沙量层化效应和制约沉速对底部高含沙层具有重要影响。提出的平底床面含沙量剖面表达式为幂函数-Rouse-指数分布，漩涡沙波床面为指数-幂函数-Rouse分布。预期可应用于二维和三维泥沙数值模拟。
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| 关 键 词： | 高含沙层 床面形态 泥沙扩散系数 含沙量剖面 细颗粒泥沙 |
| 收稿时间： | 2018-09-03 |
Numerical simulation of flow-sediment dynamics in wave-current bottom boundary layer: III: simulation of high concentration near the bottom |
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| ZUO Liqin,LU Yongjun,ZHU Hao.Numerical simulation of flow-sediment dynamics in wave-current bottom boundary layer: III: simulation of high concentration near the bottom[J].Advances in Water Science,2019,30(6):810-822. |
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| Authors: | ZUO Liqin LU Yongjun ZHU Hao |
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| Institution: | State Key Laboratory of Hydrology, Water Resources and Hydraulic Engineering, Nanjing Hydraulic Research Institute, Nanjing 210029, China |
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| Abstract: | Studies of the high concentration layer (HCL) have great theoretical and practical significance in the protection and utilization of estuarial and coastal areas. In order to better understand the HCL,the physical impacting mechanisms and phase-averaged sediment concentration profile were studied. Combining a 1DV model for the flow-sediment dynamics in the wave-current bottom boundary layer (BBL) and experimental data sets,sensitivity analyses were performed by carrying out computations of several scenarios. Inspired by the 1DV model,the distribution of wave-related sediment diffusivity was proposed,and process-based expressions for the suspended sediment concentration (SSC) profile were derived considering primary impacting factors. Results showed that the HCL is directly related to the wave BBL,which is a combined result of bed forms and flow dynamics. It is not appropriate to establish the relationship of the HCL with a single factor,for instance,the parameters of flow dynamics or bed forms. The effects of stratification and the hindered settling velocity have significant impacts on the HCL. The proposed SSC profile over a flat bed is a distribution of power-Rouse-exponent,while over a vortex rippled bed,it has an exponent-power-Rouse distribution. It is expected that these expressions can be applied in further 2-D and 3-D simulations. |
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| Keywords: | high concentration layer bed forms sediment diffusivity sediment concentration profile fine sediment |
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