期刊名称：IOP Conference Series: Earth and Environmental Science
印刷版ISSN：1755-1307
电子版ISSN：1755-1315
出版年度：2018
卷号：199
期号：2
页码：022034
DOI：10.1088/1755-1315/199/2/022034
语种：English
出版社：IOP Publishing
摘要：Flows in river bend present complex patterns that play an important role for river regulation and control. Experiments were conducted to investigate the evolution of the main flow in a U-shape flume (both of the inflow and outflow segments are 11m long). A Particle Image Velocity system (PIV) was used to measure the streamwise-vertical velocity fields at seven sections along the flume. Three cases (flow depth=4, 5, and 6 cm respectively) have been studied. Three major features of the flow have been revealed. Firstly, the maximum velocity occurs near the inner-side of the entrance of the bend, and it turns to the external side later and remains so all the way to the bend end. The exact position of the deflecting position is logarithmically related to the flume width B, centerline radius RC and water depth H. Secondly, the flow shows dramatic change at around the 1/5 of the bend, where the deflecting position and the maximum velocity occur near the inner bank. Thirdly, with the combined effect of water surface slope, gravity and centrifugal force, the axis of the maximum velocity goes down along the bend and this trend becomes stronger with the increase of H. Results in this study provide real data for verifying mathematical models and for reference in practical engineering.
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