水科学进展2026，Vol.37Issue(3)：563-573,11.DOI:10.14042/j.cnki.32.1309.2026.03.014
明渠湍流结构对泥沙颗粒起动作用机理
Mechanism of sediment particle incipient motion governed by turbulent structures in open channel flows
摘要
Abstract
The critical condition for sediment incipient motion is a foundational issue in the field of fluvial hydraulics.Recent studies on turbulence have uncovered the existence of turbulent structures across various scales in open-channel flows,including very-large-scale motions(VLSMs),large-scale motions,and small-scale motions.Nevertheless,research investigating sediment incipient motion through the perspective of turbulent structures is still in its early stages,and substantial controversy remains regarding the dominant turbulence scales and their underlying mechanisms.In the present work,100 sets of sediment incipient motion experiments are conducted using a particle image velocimetry(PIV)system.A continuous wavelet transform is employed to examine the transient characteristics of turbulent structures across various scales during the sediment incipient motion.The findings indicate that,under the present experimental conditions,VLSMs dominate up to 76.0％of sediment incipient motion events.Additionally,theoretical analysis suggests that the fluctuating drag force is primarily governed by the streamwise fluctuating velocity and the increase in turbulent kinetic energy(TKE).As sediment particles approach the critical condition for incipient motion,the intensity of VLSMs substantially escalates.This accounts for 74.0％of the streamwise fluctuating velocity and 59.3％of the increase in streamwise TKE,establishing VLSMs as the predominant turbulent structure responsible for sediment incipient motion.关键词
泥沙起动/湍流结构/超大尺度运动/连续小波变换/脉动拖曳力Key words
sediment incipient motion/turbulent structures/very-large-scale motions(VLSMs)/continuous wavelet transform(CWT)/fluctuating drag force分类
建筑与水利引用本文复制引用
沈颖,刘洁,肖毅,杨胜发..明渠湍流结构对泥沙颗粒起动作用机理[J].水科学进展,2026,37(3):563-573,11.基金项目
国家自然科学基金项目(52179059) （52179059）
重庆市教委科学技术研究项目(KJQN202400714) *The study is financially supported by the National Natural Science Foundation of China(No.52179059)and the Science and Technology Research Program of the Chongqing Municipal Education Commission,China(No.KJQN202400714). （KJQN202400714）
