摘要
推移质运动速度是研究推移质运动规律的最基本要素之一,其受水流强度、床面结构、泥沙补给等多方面影响,显著影响着河道输沙率与河床演变过程。基于当量粗糙高度条件下两种床面布置的推移质颗粒运动概化试验,分析了颗粒运动速度的时均特征和概率密度分布。试验结果表明:在保证颗粒连续运动的水流条件下,矩形密排床面上颗粒主要沿流向运动,速度表现为“加速-减速-加速”的周期特征;梅花形密排床面上颗粒展向摆动幅度和频率明显增大,其他运动特征与矩形密排床面情况基本一致。流向速度概率密度分布呈Gamma分布;展向速度概率密度分布服从正态分布;梅花形密排床面展向速度范围更分散,表明当量粗糙高度条件下不同床面布置型式对颗粒运动速度大小产生一定影响,但颗粒运动速度的概率统计特征趋向一致。
The velocity of bedload particles is one of the fundamental parameters in studying bedload transport processes.It is influenced by various factors such as flow intensity,bed structure,and sediment supply,and it significantly affects sediment transport rates and riverbed evolution.Based on simplified experiments on bedload particle motion over two bed configurations under conditions of equivalent roughness height,the time-averaged characteristics and probability density distributions of particle velocity were analyzed.The experimental results show that,under flow conditions sufficient to maintain continuous particle motion,particles on the rectangular packed bed predominantly move longitudinally,exhibiting a periodic pattern of"acceleration-deceleration-acceleration".On the plum blossom packed bed,lateral oscillation amplitude and frequency increase significantly,while other motion characteristics remain similar to those on the rectangular bed.The probability density distribution of longitudinal velocity follows a Gamma distribution,while that of lateral velocity follows a normal distribution.The lateral velocity distribution on the plum blossom bed is more dispersed,indicating that under equivalent roughness height conditions,different bed configurations exert a certain influence on the magnitude of particle velocity,but the statistical characteristics of particle velocity tend to be consistent.
作者
吴建民
肖毅
邓敬宏
WU Jianmin;XIAO Yi;DENG Jinghong(School of River&Ocean Engineering,Chongqing Jiaotong University,Chongqing 400074,China;National Engineering Research Center for Inland Waterway Regulation,Chongqing Jiaotong University,Chongqing 400074,China)
出处
《水道港口》
2025年第6期861-867,895,共8页
Journal of Waterway and Harbor
基金
国家重点研发计划资助项目(2023YFB2604700)。
关键词
推移质运动
床面型式
概率密度
水流强度
粗糙度
流速
bedload movement
bed form
probability density
water flow intensity
roughness
flow velocity
