Turbulence structure and coherent motion in meandering compound open-channel flows
Turbulence structure and coherent motion in meandering compound open-channel flows
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DOI：
10.3826/jhr.2009.3485
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发表时间：
2009-09
影响因子：
2.3
通讯作者：
M. Sanjou;I. Nezu
中科院分区：
文献类型：
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作者：
M. Sanjou;I. Nezu
曲流复式明渠水流是河道工程和洪水灾害研究的热点。特别是，横截面的二次电流的发展显着相关的曲折的inbank主通道流和直漫滩流之间的相互作用。这些水流促进了它们之间的质量和动量交换，以及沉积物搬运和河床侵蚀。此外，可以以与直复合通道中的典型水平涡流相同的方式产生有组织的运动。然而，有组织的运动和二次电流的产生过程的详细信息是有限的。利用多层扫描PIV技术研究了复合明渠流由直向弯过渡区的水平相干运动的三维结构及其平流特性，并与连续弯槽流的结果进行了对比，得到了水平涡与二次流之间的密切关系，建立了唯象流模型。
Meandering compound open-channel flow is of high interest in river engineering and flood disaster. In particular, cross-sectional secondary currents develop significantly associated with an interaction between meandering inbank main-channel flow and straight overbank floodplain flow. These currents promote mass and momentum exchanges between them, as well as sediment transport and bed erosion. Further, organized motions may be generated in the same manner as typical horizontal vortices in straight compound channels. However, there is limited detailed information on the generation process of organized motion and secondary currents. This study focuses on the 3D structure of horizontal coherent motion and its advection property in the channel-transition zone from the straight to meandering compound open-channel flows by using a multi-layer scanning PIV, and compares them with those of continuous meandering channel flows.A strong relation between the horizontal vortices and secondary currents was obtained, resulting in a phenomenological flow model.