Flow Analysis of a River Confluence with Field Measurements and Rans Model with Nested Grid Approach
Flow Analysis of a River Confluence with Field Measurements and Rans Model with Nested Grid Approach
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DOI：
10.1002/rra.2718
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发表时间：
2015-01
影响因子：
2.2
通讯作者：
S. Baranya;N. Olsen;J. Józsa
中科院分区：
文献类型：
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作者：
S. Baranya;N. Olsen;J. Józsa
通过三维雷诺平均纳维尔-斯托克斯模型对匈牙利两条中型河流（Qmean = 30-50 m3/s）交汇处进行了全面的流量分析。该模型进行了验证，详细的固定和移动声学多普勒海流剖面仪流速剖面。在结构化网格上进行了稳态边界条件下的非稳态模拟，以揭示水流的大尺度空间特性，例如由于汇流上游的河流弯曲而产生的强烈二次流。二次流矢量指示的旋流特性的流动来自现场测量和模型结果显示出良好的协议，为两个不同的流量比。此外，一种新的方法被用来模拟非定常涡脱落实施嵌套网格到以前使用的粗网格。采用相当精细的水平（~0.5 m）和时间（1 s）分辨率，数值模型再现了两条河流之间的水流的非定常特性。还通过2010年发生的灾难性赤泥泄漏中和所用石膏羽流的传播实例，介绍了混合过程的定性评估。结果表明，二次流和旋涡脱落的综合影响。版权所有© 2013约翰威利父子有限公司.
A comprehensive flow analysis for a confluence of two medium‐sized (Qmean ≈ 30–50 m3/s) Hungarian rivers was carried out by means of a three‐dimensional Reynolds‐averaged Navier–Stokes modelling. The model was validated against detailed fixed and moving Acoustic Doppler Current Profiler velocity profiling. Unsteady simulations with steady‐state boundary conditions were performed on a structured grid in order to reveal the characteristic large‐scale spatial behaviour of the flow, such as strong secondary currents because of the river bends upstream of the confluence. Secondary current vectors indicating the swirling character of the flow were derived both from field measurements and model results showing good agreements for two different discharge ratios. Additionally, a novel approach was used to simulate the unsteady vortex shedding implementing a nested grid into the previously used coarse grid. Using a considerable finer horizontal (~0.5 m) and time (1 s) resolution, the numerical model reproduced the unsteady character of flow between the two rivers. A qualitative assessment of the mixing processes was also introduced through the example of the propagation of plaster plume used to neutralize a disastrous red mud spillage that occurred in 2010. The results indicate the combined influence of secondary currents and vortex shedding. Copyright © 2013 John Wiley & Sons, Ltd.