Experimental Study of Sediment Incipience Under Complex Flows  

作　　者：LIU Chunrong DENG Liying HUANG Zhenhua HUHE Aode 

机构地区：[1]Maritime Research Center, School of Civil and Environmental Engineering Nanyang Technological University, Singapore 639798 [2]College of Mechanics and Aerospace, Hunan University, Changsha 410082, China [3]School of Civil and Environmental Engineering, Nanyang Technological University, Singapore 639798 [4]Institute of Mechanics, Chinese Academy of Sciences, Beijing 100080, China

出　　处：《Transactions of Tianjin University》2008年第4期300-306,共7页天津大学学报（英文版）

基　　金：National Natural Science Foundation of China (No.10602017);Maritime Research Center and DHI-NTU Center of Nanyang Technological University, Singapore

摘　　要：Sediment incipience under flows passing a backward-facing step was studied. A series of experiments were conducted to measure scouring depth, probability of sediment incipience, and instantaneous flow velocity field downstream of a backward-facing step. Instantaneous flow velocity fields were measured by using Particle Image Velocimetry (PIV), and an image processing method for determining probability of sediment incipience was employed to analyze the experimental data. The experimental results showed that the probability of sediment incipience was the highest near the reattachment point, even though the near-wall instantaneous flow velocity and the Reynolds stress were both much higher further downstream of the backward-facing step. The possible me- chanisms are discussed for the sediment incipience near the reattachment point.Sediment incipience under flows passing a backward-facing step was studied. A series of experiments were conducted to measure scouring depth, probability of sediment incipience, and instantaneous flow velocity field downstream of a backward-facing step. Instantaneous flow velocity fields were measured by using Particle Image Velocimetry （PIV）, and an image processing method for determining probability of sediment incipience was employed to analyze the experimental data. The experimental results showed that the probability of sediment incipience was the highest near the reattachment point, even though the near-wall instantaneous flow velocity and the Reynolds stress were both much higher further downstream of the backward-facing step. The possible mechanisms are discussed for the sediment incipience near the reattachment point.

关 键 词：sediment transport local scour complex flows particle image velocimetry sediment incipience 

分 类 号：TV142[水利工程—水力学及河流动力学]