Water flow and sediment transport at open-channel confluences: an experimental study
Water flow and sediment transport at open-channel confluences: an experimental study
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DOI：
10.1080/00221686.2017.1354932
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发表时间：
2018-05
影响因子：
2.3
通讯作者：
Saiyu Yuan;Hongwu Tang;Yang Xiao;Xuehan Qiu;Yang Xia
中科院分区：
文献类型：
--
作者：
Saiyu Yuan;Hongwu Tang;Yang Xiao;Xuehan Qiu;Yang Xia
摘要 由于过去大多数研究都集中在自然河流交汇处，因此对城市河道交汇动态的了解还不够。本文报告了城市交汇处的河床形态和水动力及其对流量比的依赖性的实验观察。识别了典型的流体动力学和形态特征，例如剪切层、螺旋细胞、杆和冲刷孔。然而，小流量比下的低速流区域的存在与之前的研究结果不同。与冲刷孔侵蚀沉积物走廊相关的两个沙脊合并成一个中流坝。结果还表明，螺旋运动中的下降流和上升流对床层的强烈剪切是造成中流冲刷孔的原因。
ABSTRACT The knowledge of the dynamics of urban channel confluences is insufficient as most past studies have focused on natural river confluences. This paper reports experimental observations on bed morphology and hydrodynamics of the urban confluences and their dependence to the discharge ratio. Typical hydrodynamic and morphological features such as the shear layer, helical cells, bars and scour holes are identified. Nevertheless, the presence of a region of low-velocity flow for a small discharge ratio differs from results obtained in previous studies. Two sand ridges associated with the corridors of the eroded sediment from the scour holes merge into a mid-stream bar. Results also show that the intense shear towards the bed by downwelling and upwelling flows involved in helical motions is responsible for the mid-stream scour hole.