| 异侧布置竖缝式鱼道紊流结构试验研究 |
| An Experimental Study of Turbulent Flow Structures in a Vertical Slot Fishway with Staggered Slots |
| 投稿时间：2019-02-27 修订日期：2021-01-21 |
| DOI：10.15928/j.1674-3075.201902270049 |
| 中文关键词:竖缝式鱼道 水平旋涡 三维流速分布 紊动强度 雷诺应力 |
| 英文关键词:vertical slot fishway horizontal vortex three-dimensional velocity distribution turbulence intensity Reynolds stress |
| 基金项目:国家自然科学基金（51779225） |
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| 中文摘要: |
| 鱼道是辅助鱼类克服障碍物实现产卵洄游、索饵洄游和越冬洄游的通道。全球目前已建鱼道中，鱼类能够溯游通过的鱼道尚不足50%，大多数鱼道的水力设计仅考虑平均流速，忽略了鱼道内的紊流结构，探究鱼道的水力特性尤其是其紊流结构，对改进其设计具有重要的指导意义。通过在大比尺鱼道水槽模型中试验研究异侧布置竖缝式鱼道的紊流结构，利用声学多普勒测速仪（ADV）实测竖缝式水池内每一点的三维瞬时流速，剖析流场的三维时均流速分布、流动特征、旋涡特性、纵向和横向紊动强度分布、不同水平面的雷诺应力分布等，考虑了两种典型流量（Q1=20.62 L/s，Q2=30.75 L/s）和3个特征水平面（h/3，h/2和2h/3），提出了三维流速分布的半理论半经验公式、流场矢量图及各点的旋度，并与自由壁面射流进行比较。结果表明，异侧布置竖缝式鱼道前半池内纵向流速具有壁面射流的特征，后半池由于受下游隔板的阻挡则偏离壁面射流规律；水槽内存在以顺时针方向旋转的水平旋涡，其旋度随流量的增大而增强；前半池壁面射流区的紊动强度存在峰值区，后半池的紊动强度峰值区由水槽左侧移至右侧；壁面射流区的雷诺应力变化幅度较大，而在旋涡区则较小，有利于洄游鱼类在鱼道内上溯和歇息。 |
| 英文摘要: |
| Fishways are constructed to help fish overcome obstacles as they migrate to spawn, feed or overwinter. However, data indicates that fishways in which most fish successful pass make up no more than half of the world’s fishways. Up to now, the hydraulic design of fishways has tended to focus on mean velocity and neglected the turbulent flow generated in fishways. Research has shown that fish can detect turbulence by the inner ear, lateral line and nerve hillock. Thus, when research is conducted to improve fishway design, the turbulent structures produced in the fishway must be considered. In this study, the turbulent structures produced in a staggered vertical slot were studied in a large-scale model of a fishway flume. Three-dimensional instantaneous velocities at each point were measured using Acoustic Doppler Velocimetry (ADV). The three-dimensional time-averaged velocity distribution, flow characteristics, vortex behavior, the intensity distribution of longitudinal and transverse turbulence, and the Reynolds stress distribution on three horizontal planes (h/3，h/2 and 2h/3) were analyzed at two typical flow rates (Q1=20.62 L/s and Q2=30.75 L/s). Semi-theoretical and semi-empirical formulas of the three-dimensional velocity distribution, a velocity vector chart and the rotation index at each point in the flow field were developed, and a comparison was made with a free wall jet. The experimental results show that the longitudinal velocity was influenced primarily by the wall jet in the first semi-pool of the staggered vertical slot fishway, but deviates from the wall jet pattern as a result of obstruction by the lower baffle of the second semi-pool. A clock-wise horizontal vortex is produced, and its rotation index increases with flow rate. Turbulence intensity peaked in the first semi-pool and the peak turbulence moved from left to right in the second semi-pool. The Reynolds stress amplitude is larger in the wall jet zone and smaller in the vortex zone, thus assisting migratory fish as they swim upstream and providing rest within the fishway. |
| 董志勇,江录兵,毛 斌,陈欣宇.2021.异侧布置竖缝式鱼道紊流结构试验研究[J].水生态学杂志,42(1):129-136. |
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