| 摘要: |
| 开展一系列开闸式斜坡泥沙异重流水槽实验，采用高速相机记录异重流发展过程，并利用声学多普勒流速仪（acoustic doppler velocimeter，ADV）获取泥沙异重流的速度、浓度及湍流结构，探究刚性植被对异重流运动特性的影响。实验结果表明：随着植被高度的增大，泥沙异重流的头部与尾部发生分离，且植被高度对异重流头部速度削减作用的重要性大于植被密度；受植被作用的影响，异重流速度剖面的峰值位置和峰值大小均发生改变；此外，由于植被与异重流相互作用产生的湍流，使异重流的泥沙浓度剖面发生改变，并使悬浮于流体中的泥沙颗粒向上输运。本研究的结论对自然环境保护、水下工程建设等生产实际问题提供重要的科学依据。 |
| 关键词: 泥沙异重流 斜坡 刚性植被 湍流 |
| DOI：10.11693/hyhz20201200340 |
| 分类号:TV145 |
| 基金项目:国家重点研发计划，2017YFC0405205号；国家自然科学基金资助项目，11672267号，41876089号；舟山市科技计划项目浙江大学海洋学院专项，2018C81034号；浙江省自然科学基金资助项目，LY20A020009号；中央高校基本科研业务费专项资金，2020QNA4038号。 |
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| EFFECT OF RIGID VEGETATION ON DYNAMICS AND TURBULENCE OF SEDIMENT GRAVITY FLOW DOWNSLOPE |
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WANG Yu-Hang1, HAN Dong-Rui1, WU Ting-Feng2, LIN Ying-Dian1
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1.Ocean College, Zhejiang University, Zhoushan 316021, China;2.State Key Laboratory of Lake Science and Environment, Nanjing Institute of Geography and Limnology, Chinese Academy of Sciences, Nanjing 210008, China
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| Abstract: |
| A series of flume experiments were conducted to simulate gravity currents on sluice-opening downslope. The development course of particle-laden gravity currents was videoed with a high-speed camera, in which the velocity, concentration, and turbulence structures of turbidity currents were acquired using acoustic Doppler velocimeter (ADV) to understand the dynamics of particle-laden gravity currents under the effects of rigid vegetation. Results show that with the increase of vegetation height, the head and tail of particle-laden gravity currents were separated, and the vegetation height was more effect than the vegetation density on reducing the front velocity. Due to the presence of vegetation, both the peak velocity and the corresponding position shown in the velocity profile changed. In addition, the turbulence caused by the interaction between vegetation and gravity currents changed the sediment concentration profile and underpinned the suspended sediment particles upward. The findings of this study provide a significant scientific basis for solving engineering issues relative to natural environment protection and underwater engineering construction. |
| Key words: particle-laden gravity currents downslope rigid vegetation turbulence |
