粗颗粒泥沙起动概率研究综述

Literature Review of Entrainment Probability of Coarse-Grained Sediment

泥沙起动作为泥沙运动力学和河流动力学的基本问题之一,对河床演变、渠道冲刷、推移质输沙率的确定等都具有重要意义。受水流紊动、泥沙颗粒床面位置随机等因素影响,粗颗粒泥沙的受力呈现出脉动的特性,从而使得其起动与否具有很强的随机性,故采用概率论方法来描述泥沙起动更切合其本质。根据起动条件,可将起动概率研究分为基于瞬时的作用力和基于冲量的作用力。通过系统分析,总结了近几十年来起动概率及其影响变量的相关研究,对明渠湍流相干结构研究的发展和泥沙起动机理认识也逐步深入,为进一步深化泥沙起动概率的研究奠定基础。

Sediment entrainment is one of the basic problems of sediment transport mechanics and river dynamics,which is of great importance for the evolution of riverbed,channel scouring,and determination of bed-load sediment transport rate.Influenced by multiple factors,such as flow turbulence and the random position of sediment particles on bed,the forces acting on coarse sediment particles were also pulsating,resulting in strong randomness in their entrainment.Therefore,the probabilistic approach is appropriate to describe the entrainment of sediment motion.According to the incipient conditions,the research on entrainment probability can be divided into that based on instantaneous forces and that based on impulse.Through systematic analysis and summary of relevant research on the entrainment probability and its influencing variables in recent decades,the development of research on the coherent structure of turbulent flow in open channels and the gradual deepening of understanding of sediment initiation mechanisms have laid the foundation for further deepening the research on sediment entrainment probability.