无黏性非均匀沙分级起动流速研究  

Study on the graded starting velocity of non-viscous non-uniform sediment

作　　者：许晓阳 张根广[1] 周双[1] 麻卉港 XU Xiao-yang;ZHANG Gen-guang;ZHOU Shuang;MA Hui-gang(College of Water Resources and Architectural Engineering,Northwest A&F University,Yangling 712100,China)

机构地区：[1]西北农林科技大学水利与建筑工程学院,陕西杨凌712100

出　　处：《泥沙研究》2022年第5期1-7,共7页Journal of Sediment Research

基　　金：国家自然科学基金项目(51879227,51279170)。

摘　　要：为进一步完善非均匀沙的起动规律,分析了非均匀沙起动的随机特性,借鉴可反映下游泥沙颗粒粒径影响的暴露度参数,引入泥沙起动全概率的概念,采用滚动起动模式,推导了反映水流条件随机性和床沙位置分布规律的非均匀沙分级起动概率公式。以非均匀沙分级起动概率重新定义泥沙起动标准,得到泥沙起动概率与起动标准的一一对应关系。构建了反映泥沙起动随机特性的非均匀沙分级起动流速公式,该公式可转化为均匀沙起动流速公式。采用实测资料及经典的泥沙起动流速公式,对本文泥沙起动流速公式进行了验证,结果表明,本文公式可以很好地预测非均匀沙和均匀沙的起动流速。The stochastic characteristics of non-uniform sediment incipient motion are analyzed.By referring to the exposure parameters,the concept of total probability of sediment incipient motion was introduced,and the rolling start mode was adopted to derive the entrainment probability formula of non-uniform sediment of indivi-dual fractions,which reflected the randomness of flow conditions and the distribution of sediment positions.The initiation standard of non-uniform sediment was redefined based on the probability of non-uniform sediment of individual fractions,and the correspondence between the entrainment probability and initiation standard was obtained.The incipient motion velocity formula of non-uniform sediment was constructed to reflect the random characteristics of sediment starting,and the formula could be transformed into the incipient motion velocity formula of uniform sediment.Based on the observed data and the classical incipient motion velocity formula of sediment,the incipient motion velocity formula of sediment is verified.The results show that the formula can predict the incipient motion velocity of non-uniform sediment and uniform sediment well.

关 键 词：非均匀沙 分级起动 随机理论 起动概率 起动流速 

分 类 号：TV142.2[水利工程—水力学及河流动力学]