阵性泥石流泥位过程线的Euler-Lagrange分析  

Analyses on flow depth hydrograph of debris-flow surges in Euler and Lagrange coordinate systems

作　　者：胡凯衡[1,2] 康志成[1,2] 李泳[1,2] 

机构地区：[1]中国科学院山地灾害与地表过程重点实验室,四川成都610041 [2]中国科学院-水利部成都山地灾害与环境研究所,四川成都610041

出　　处：《泥沙研究》2010年第4期6-10,共5页Journal of Sediment Research

基　　金：中科院知识创新重要方向项目(KZCX2-YW-302);国家自然科学青年科学基金项目(40701014);中科院成都山地灾害与环境研究所创新工程项目资助

摘　　要：自然界中的泥石流往往表现为多阵次的间歇来流。云南蒋家沟实测的阵性流泥位过程线接近于幂函数,与通常认为的线性函数存在较大误差。本文基于阵性流泥位过程线在Euler坐标和Lagrange坐标下两种形状的转换关系,得到充分发展阵性流的泥位与历时、断面平均流速与泥位之间呈幂律关系,而且两者的幂律指数相关。从实测数据的拟合结果得到前者的幂律指数n约为-0.6417,由此推出后者的指数接近于2.56。最后根据幂律流体的断面流速公式,讨论了泥石流流变指数与n的关系。这为泥石流的流速计算和流变性质等的研究提供了一种全新的方法。A debris-flow event consists of many intermittent surges,which distinguishes debris flow from flood and sediment-laden flow.The surge’s hydrograph has been described traditionally as linear graph,so triangle method is used to calculate one surge’s bulk volume.After investigating witness by sight and measured data by ultrasonic sensor in Jiangjia Ravine,Yunnan Province,we propose that linear and non-linear hydrographs are just two different forms of a debris-flow surge in Lagrange and Euler reference frames,and the triangle method will cause a big error.Then,on the condition of fully developed surge,the dependences of flow depth on time,and of transverse-averaged velocity on flow depth are modeled as power functions.The power index n of the flow-depth and time function is equal to-0.6417 according to the result fitted from the measured data.Because the power index of the velocity and flow-depth function is equal to n-1/n,the velocity is approximately proportional to 2.56 power of the depth.Finally,we discuss the relationship between the index n and the flow index of debris flow.

关 键 词：泥石流 阵性流 流量过程线 流变指数 

分 类 号：TV144[水利工程—水力学及河流动力学]