淹没出流条件下小挑角挑流消能工消能特性研究  

Study on energy dissipation characteristics of trajectory energy dissipater with small-trajectory angle under submerged outflow condition

作　　者：熊长鑫 梅家鹏 董宗师 XIONG Changxin;MEI Jiapeng;DONG Zongshi(CISPDR Corporation,Wuhan 430010,China)

机构地区：[1]长江设计集团有限公司,湖北武汉430010

出　　处：《水利建设与管理》2022年第12期13-18,共6页Water Conservancy Construction and Management

摘　　要：挑流消能工广泛应用于高水头泄洪建筑物消能,但目前大部分挑流消能工多为自由出流工况,在淹没出流条件下应用较少。本文采用三维CFD技术对咸丰丁寨泄洪排涝隧洞淹没出流工况下小挑角消能工的泄洪流态及消能效果进行研究。首先对比了自由出流和淹没出流下挑流消能的消能特性,然后分析了不同频率洪水下挑流消能的三维流态、湍动能及消能率。结果表明:小挑角挑流在下游水位较低时,挑射水舌类似于跌流消能;当下游水位较高时,隧洞出流主流与尾水水流撞击,类似于面流消能。由于小挑角下,挑射水流纵向拉伸不够,难以形成挑射水舌,消能效果不佳,本工程各频率泄洪条件下消能工的消能率均低于70%,建议优化消能工体形,提高消能效果。该研究可为淹没条件下的挑流消能工设计提供参考。Trajectory energy dissipaters are widely applied in the energy dissipation for high head flood discharge buildings.However,most of trajectory energy dissipaters are under the condition of free outflow,which are rarely applied under submerged outflow condition.In this paper,3D CFD technology is used to study the discharge flow and energy dissipation effect of small-trajectory angle energy dissipater under submerged outflow condition of Xianfengdingzhai flood discharge tunnel.Firstly,the energy dissipation characteristics of trajectory energy dissipation under free outflow and submerged outflow are compared.Then,the three-dimensional flow pattern,turbulence energy and energy dissipation rate of trajectory energy dissipation under floods with different frequency are analyzed.The results show that when the water level is low in the downstream,the jet nappe is similar to underflow energy dissipation.When the water level is high in the downstream,the main flow of the tunnel impinges with the tail water,which is similar to surface energy dissipation.Due to the insufficient longitudinal stretch of the outflow water at small-trajectory angle,it is difficult to form the jet nappe and the energy dissipation effect is not good.The energy dissipation rate of the energy dissipaters is lower than 70%under the flood discharge conditions of each frequency in this project.It is suggested to optimize the shape of the energy dissipaters to improve the energy dissipation effect.This study can provide reference for the design of energy dissipater under submerged outflow condition.

关 键 词：挑流消能 淹没出流 水流流态 湍动能 消能率 

分 类 号：TV653.3[水利工程—水利水电工程]