Numerical Study of Vertical Slot Fishway Flow with Supplementary Cylinders

Water

Hanqing Zhao¹  Jie Dai²  Dinghua Meng²  Yang Lu³  Shanshan Lu⁴  Yun Xu⁵ 

[1] China Three Gorges Corporation, Wuhan 430010, China;College of Water Conservancy and Hydropower Engineering, Hohai University, Nanjing 210098, China;Department of River and Harbor Engineering, Nanjing Hydraulic Research Institute, Nanjing 210024, China;Shanghai Investigation Design & Research Institute Co., Ltd., Shanghai 200439, China;Zhejiang Institute of Communication Co., Ltd., Hangzhou 310000, China;

关键词: vertical slot fishway;    turbulence;    large-eddy simulation;    fish swimming;   

DOI  :  10.3390/w14111772

来源: DOAJ

【 摘 要 】

The vertical slot fishway (VSF) is one of the most common types of fishway facilitating migratory fish movement past obstacles in rivers, such as dams. The uniform vertical distribution of velocity is friendly to fishes with different depth preferences, but unfriendly to fishes with different swimming capacities. For an established VSF, the insertion of an additional structure is a more convenient and effective way to change the flow field rather than altering the original elements. Numerical experiments were carried out using large-eddy simulation (LES) to optimize a typical VSF with supplementary cylinders for fishes with low swimming capacity. The computational domain of the original design is idealized as a box including two pairs of baffles with the periodic boundary condition used in the streamwise direction. The numerical model is well validated by comparison of time-averaged velocity and turbulence kinetic energy with the ADV measurements at gauging points and lines. Two arrangements of cylinders with different numbers and diameters were investigated and compared with the original design based on the first and second-order hydrodynamic statistics at the half height of the VSF. The insertion of cylinders significantly alters the flow field by introducing a branch path of relatively low-speed current. The arrangement of four slim cylinders slightly outperformed that of one thick cylinder against velocity homogeneity along the minor migration path. Although the turbulence intensity is enhanced due to the additional cylinders, the perturbation on fishes is not significant due to the small size of these vortices.

【 授权许可】

Unknown