高坝过鱼设施集诱鱼进口水力学条件数值模拟与模型试验研究

Numerical Simulation and Model Test Study on the Hydrodynamic Conditions of Fish Luring Inlet of Fish-crossing Facility in High Dams

集诱鱼设施是高坝过鱼设施的关键组成部分,其进口位置的水力学条件决定了过鱼设施的过鱼效率。为了寻找河道中满足集诱鱼设施进口水力学条件的区域,本文以某高坝工程为例,根据相关调查结果,确定了7种过鱼对象,提出了集诱鱼进口所需要满足的2种水力学条件,即流速范围为0.41～1.00 m/s,紊动能范围为0～0.04 m^2/s^2。采用标准k-ε紊流模型和VOF方法追踪自由液面,对过鱼季节不同机组运行条件下尾水下游1 km河道范围进行了3维紊流数值模拟,来研究河道中紊动能和流速的空间分布,并通过比尺为1:50的物理模型试验验证了数值模拟的合理性。结果表明,不同机组运行条件下主流靠左岸一侧均存在上溯通道,河道左岸紊动能均小于0.04 m^2/s^2;从流速分布来看,满足流速条件的区域面积分别为35 732、22 659、12 201 m^2;在河道左岸存在面积为1 354 m2的区域在不同机组运行条件下能够同时满足紊动能和流速2种水力学条件,该区域能产生良好的集诱鱼水流,集诱鱼效果较好,即集诱鱼进口适宜布置该区域内。

The fish collecting and luring facility was the key component of high-dam fish-crossing facilities.The fish-passing efficiency of fish passing facilities was determined by the hydraulic conditions near the inlet.In order to find out the areas where the hydraulic conditions of the inlet of the fish luring facility were satisfied,this paper took a high dam project as an example.According to the related survey results,seven kinds of over-fishing objects were identified,and two kinds of hydraulics conditions that met the requirements of the fish luring inlet were proposed,i.e.,the flow range was 0.41~1.00 m/s and the turbulence energy range was 0~0.04 m2/s2.The three-dimensional numerical simulations were conducted by using the standard k-εturbulence model and the VOF method to track the free surface of the water,simulating 1 km long river downstream of the tailrace tunnel under different operational condition of generator sets during the fish crossing seasons.The simulation aimed to study the turbulence energy and velocity in the river.The numerical model was verified by the physical model test with the model scale of 1:50.The results showed that under different operational conditions of generator sets,there existed an upstream fish passage channels along left side of bank with the turbulence energy less than 0.04 m2/s2 on all conditions,and according to the distribution of flow velocity,the areas of the passage channel meeting the flow rate conditions were respectively 35 732,22 659 and 12 201 m2,respectively.According to the study,it was found that there was a 1 354 m2 area in the left bank that satisfies both hydraulics conditions of turbulence energy and flow velocity.This area was suitable for arranging the inlet of the fish collecting and luring facility.