低水头电站导墙布置对进水口流态的影响

以某低水头水利枢纽电站工程布置为实例,首先采用物理模型的方法,观测分析了导墙布置对电站进水口流态的影响,并针对导墙附近形成的局部漩涡予以理论分析,提出导墙附近漩涡的形成规律;然后利用标准k-ε紊流模型对各工况进行了数值模拟,在此基础上,进一步从三维流态、断面流速分布及紊动能等方面,分析了影响电站进水口流态的因素,即在水力要素一定的情况下,导墙长度对进水口断面流速分布存在一个临界长度,为今后其他工程电站导墙布置提供了参考,有一定的借鉴意义。

Influence of Guide-wall Layout of Low-head Power Station on the Flow Pattern at the Intake

With a low head hydropower station as case study,we observed and analyzed the influence of guide-wall design on the flow pattern at the intake of the station through physical model.Having theoretically analyzed the local vortex near the guide-wall,we presented the law of the formation of vortex near the guide-wall.Furthermore,based on numerical simulation of different working conditions through standard k-ε turbulence model,we analyzed the 3-D flow pattern,the section flow velocity distribution,and the turbulent kinetic energy to obtain factors affecting the flow pattern at the intake.We found that the length of guide-wall determined the lateral force on the vortex.Under certain hydraulic elements,when a critical value of guide-wall length exists,the head loss caused by vortex could be small while the discharge capacity could be optimum.This research could be referential for the design of guide-wall of power stations.