Probability of Sediment Incipient Motion Under Complex Flows  

作　　者：刘春嵘 邓丽颖 呼和敖德 

机构地区：[1]College of Mechanics and Aerospace,Hunan University [2]Institute of Mechanics,Chinese Academy of Sciences

出　　处：《China Ocean Engineering》2010年第1期93-104,共12页中国海洋工程（英文版）

基　　金：supported by the National Natural Science Foundation of China (Grant No.10602017)

摘　　要：Presented in this paper is a mathematical model to calculate the probability of the sediment incipient motion, in which the effects of the fluctuating pressure and the seepage are considered. The instantaneous bed shear velocity and the pressure gradient on the bed downstream of the backward-facing step flow are obtained according to the PIV measurements. It is found that the instantaneous pressure gradient on the bed obeys normal distribution. The probability of the sediment incipient motion on the bed downstream of the backward-facing step flow is given by the mathematical model. The predicted results agree well with the experiment in the region downstream of the reattachment point while a large discrepancy between the theory and experiment is seen in the region near the reattachment point. The possible reasons for this discrepancy are discussed.Presented in this paper is a mathematical model to calculate the probability of the sediment incipient motion, in which the effects of the fluctuating pressure and the seepage are considered. The instantaneous bed shear velocity and the pressure gradient on the bed downstream of the backward-facing step flow are obtained according to the PIV measurements. It is found that the instantaneous pressure gradient on the bed obeys normal distribution. The probability of the sediment incipient motion on the bed downstream of the backward-facing step flow is given by the mathematical model. The predicted results agree well with the experiment in the region downstream of the reattachment point while a large discrepancy between the theory and experiment is seen in the region near the reattachment point. The possible reasons for this discrepancy are discussed.

关 键 词：PROBABILITY sediment incipience backward-facing step flow SEEPAGE PRESSURE 

分 类 号：P737.14[天文地球—海洋地质]