波浪运动在底边界层的湍流结构数值研究  

Numerical investigation on the turbulent structures in the bottom boundary layers under the effects of waves

作　　者：张炫 郑金海[1] 张弛[1] Zhang Xuan;Zheng Jinhai;Zhang Chi(College of Harbor,Coastal and Offshore Engineering,Hohai University,Nanjing 210098,China;State Key Laboratory of Coastal and Offshore Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]河海大学港口海岸与近海工程学院,江苏南京210098 [2]大连理工大学海岸和近海工程国家重点实验室,辽宁大连116024

出　　处：《海洋学报》2023年第12期13-24,共12页

基　　金：国家自然科学基金项目(51909074);大连理工大学海岸和近海工程国家重点实验室开放基金项目(LP2105);中国博士后科学基金项目(2019M661713);中央高校自由探索项目(B210202024)。

摘　　要：本文基于k-ε模型研究了波流边界层内湍流结构特征。研究结果表明,时均流速分布数值解与实验结果高度吻合。一个波周期内湍流结构特征(如:涡量、湍动能、湍动能耗散率等)呈周期性变化规律,波浪作用引起涡量、湍动能及湍动能耗散率均在减速阶段减小,在波谷处达到最低值,而后在加速阶段增大,并在波峰处达到最大值。近壁面处湍流结构变化幅值较大(湍动能耗散率变化可达53%),远离壁面处变化幅值较平均值较小(仅3%)。波流边界层厚度在减速阶段增加,在加速阶段减小。本文所建立的数值模型克服了现有模型因采用“高雷诺数方法”引起的近壁区精度不高问题,可较好地描述波浪作用下湍流结构演变过程的物理机制,为河口海岸地区泥沙运动、岸滩演变及海洋可再生能源的开发利用提供一些指导意义。This paper investigates the characteristics of turbulent structures in combined wave-current boundary layers based on the standard k-ε model.Good agreements were found between the numerical results and experimental data of the time-averaged mean velocity profiles.Periodic variations of turbulence parameters within a wave cycle(i.e.vorticity magnitudes,TKE and TKE dissipation rates etc.)were observed.The vorticity magnitudes,TKE and TKE dissipation rates all decrease during the deceleration phase,reach their minimum values during the wave trough,increase during the acceleration phase and reach their maximum values during the wave crest.The variations of turbulent structures are very high in the near-wall regions(53%for TKE dissipation rates),and are quite low in the outer regions(3%for TKE dissipation rates).The wave-current boundary layer thickness increases(decreases)during the deceleration phase(acceleration phase).The model developed in this study has solved the existing issue of low accuracy in the near-bed region by previous models based on the“high Reynolds number methods”.The present model performs well in describing the physical process of turbulence variations under the effects of wave-current interaction.This can provide some guidance for the sediment transport in coastal areas,beach erosion prediction and developments of marine renewable energy.

关 键 词：波流相互作用 底部边界层 湍流 计算流体力学 k-ε模型 

分 类 号：P731.21[天文地球—海洋科学] P731.22