Velocity profile of turbulent sediment-laden flows in open-channels  

作　　者：Deyu Zhong Lei Zhang Baosheng Wu Yongqiang Wang 

机构地区：[1]State Key Laboratory of Hydroscience and Engineering, Tsinghua Univ., Beijing 100084, China

出　　处：《International Journal of Sediment Research》2015年第4期285-296,共12页国际泥沙研究（英文版）

基　　金：Acknowledgments The financial support from the National Natural Science Foundation of China （NSFC, Grant nos. 51379102 and 51039004） and the National Key Technologies R＆D Program of China during the 12th Five-Year Plan Period （No. 2012BAB05B01 ） is gratefully acknowledged.

摘　　要：In this paper, a study was carried out on the velocity profile of sediment-laden flows in open channels using a two-phase mixture model for two-phase flows. The governing equations for water-sediment mixtures were derived based on the two-fluid equations for solid-liquid two-phase flows. The drift velocity, a key variable involved in the two-phase mixture equations, was derived from the equation of momentum conservation for the solid phase. The drift velocity shows that the inertia of flow, particle turbulence, and collisions effect contribute to the dispersion of the sediment particles in turbulent flows. Using the two-phase mixture equation, the vertical velocity profile of open channel flows was obtained. Further analysis indicated that the distribution of the velocity over depth of water-sediment mixtures, composed of two different phases, is significantly affected by the turbulence of water-sediment mixtures and the density stratification. However, the velocity distribution is also affected by other factors including collisions between particles and particle turbulence as a basic feature of two-phase flows where interphase interactions inevitably mark their influence on the velocity distribution. Comparisons of this approach with observations for a wide range of experimental conditions are presented in this paper, which show that this approach agrees well with the experiments.In this paper, a study was carried out on the velocity profile of sediment-laden flows in open channels using a two-phase mixture model for two-phase flows. The governing equations for water-sediment mixtures were derived based on the two-fluid equations for solid-liquid two-phase flows. The drift velocity, a key variable involved in the two-phase mixture equations, was derived from the equation of momentum conservation for the solid phase. The drift velocity shows that the inertia of flow, particle turbulence, and collisions effect contribute to the dispersion of the sediment particles in turbulent flows. Using the two-phase mixture equation, the vertical velocity profile of open channel flows was obtained. Further analysis indicated that the distribution of the velocity over depth of water-sediment mixtures, composed of two different phases, is significantly affected by the turbulence of water-sediment mixtures and the density stratification. However, the velocity distribution is also affected by other factors including collisions between particles and particle turbulence as a basic feature of two-phase flows where interphase interactions inevitably mark their influence on the velocity distribution. Comparisons of this approach with observations for a wide range of experimental conditions are presented in this paper, which show that this approach agrees well with the experiments.

关 键 词：Velocity profileSediment-laden flowsTurbulenceOpen-channels 

分 类 号：U469.11[机械工程—车辆工程] X53[交通运输工程—载运工具运用工程]