水库浑水异重流潜入点判别条件  

Prediction criterion of turbidity current formation in reservoir

作　　者：李书霞[1,2] 夏军强[3] 张俊华[2] 刘沛清[1] 王艳平[1,2] 

机构地区：[1]北京航空航天大学航空科学与工程学院,北京100083 [2]黄河水利科学研究院,河南郑州450003 [3]武汉大学水资源与水电工程科学国家重点实验室,湖北武汉430072

出　　处：《水科学进展》2012年第3期363-368,共6页Advances in Water Science

基　　金：水利部公益性行业科研专项经费资助项目(200901015);教育部新世纪优秀人才资助项目(NCET-10-619)~~

摘　　要：泥沙淤积是影响多沙河流水库寿命的一大难题,而异重流排沙是减少库区淤积的重要措施之一。异重流的潜入现象是异重流开始形成的直观标志,研究异重流潜入条件的判别方法有助于掌握异重流在库区内的演进规律。总结了水库异重流潜入条件的定性描述及定量计算方法,指出已有的潜入点判别公式的优缺点及适用范围,改进了描述异重流运动的动量方程,同时分析了异重流流速与含沙量沿垂线不均匀分布对动量传递的影响;在此基础上提出新的异重流潜入条件判别式,并用多组室内及野外实测资料对该判别条件进行率定与验证。分析结果表明,新的计算公式可用于判别小浪底库区异重流的潜入条件。Sediment deposition is a big problem that affects the lifespan of reservoirs in heavily sediment-laden rivers. Furthermore, venting turbidity currents is an important measure to reduce the sedimentation in reservoirs, especially at the initial operation stage of the Xiaolangdi Reservoir. The occurrence of plunge point means the formation of turbidity current, and the research into the prediction of turbidity current formation can help to better understand its motion laws in reservoirs. Qualitative descriptions and quantitative calculation methods for the prediction of turbidity current formation are summarized firstly in this paper, with the shortcomings and application conditions of these methods also being given. The momentum equation for the motion of turbidity current is then deduced, and the effects of non-uniform vertical distributions of sediment concentration and velocity on the formation of plunge point are investigated. Finally, a new formula for predicting the formation of turbidity currents is proposed herein, and its predictive accuracy is validated by lots of flume and field measurements. Validated results indicate that the proposed formula can be used to predict the formation of turbidity currents in the Xiaolangdi Reservoir.

关 键 词：浑水异重流 潜入点 动量方程 Froude数 小浪底水库 

分 类 号：TV145.2[水利工程—水力学及河流动力学]