Rip current system over strong alongshore non-uniformities: on the use of HADCP for model validation
Rip current system over strong alongshore non-uniformities: on the use of HADCP for model validation
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沿岸强烈不均匀性的裂流系统：关于使用 HADCP 进行模型验证
DOI：
10.2307/25738089
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发表时间：
2009
期刊：
影响因子：
--
通讯作者：
V. Marieu
中科院分区：
文献类型：
--
作者：
B. Castelle;P. Bretel;S. Morisset;P. Bonneton;N. Bonneton;M. Tissier;C. Sotin;A. Nahon;N. Bruneau;J. Parisot;S. Capo;S. Bujan;V. Marieu
建模和理解地形控制的撕裂电流仍然是一项艰巨的任务。原因之一是缺乏大量的高空间分辨率，RIP通道附近的流场测量值。在ECORS（DGA-SHOM）密集场测量中，用固定的Eulerian电流仪器仪器进行了潮间带的内孔RIP通道。另外，在这样的系统中，第一次在撕裂电流附近（在沙洲边缘）的附近实现了水平ADCP（HADCP），以进行水平分析波诱导的电流。结果表明，HADCP提供了有关RIP颈附近剪切的独特信息，这对于模型校准特别有用。将HADCP数据与各种潮汐条件的局部流量测量结果进行了比较，显示了5 m范围的非常好的一致性。指出了对现场HADCP实施的限制和建议。将HADCP用于水平分析的RIP电流循环将受益于在断路器外部署以测量裂口头的横截面，在该横截面基本上是表面占主导地位的羽毛羽和气泡。在此RIP电流系统区域，仅在高能条件下才能遭受声学不透明度，由于电流剪切，RIP电流射流非常不稳定。 HADCP将提供有关RIP当前不稳定性和RIP当前系统领域中涡流脱落的独特信息。
Modeling and understanding topographically-controlled rip currents remains a challenging task. One of the reasons is the lack of intensive, high-spatial resolution, flow field measurements in the rip channel vicinity. During the ECORS (DGA-SHOM) intensive field measurements, an intertidal inner-bar rip channel was instrumented with fixed eulerian current meters. In addition, for the first time in such a system, a Horizontal ADCP (HADCP) was implemented in the vicinity of the rip current, on the sandbar edge, for horizontally profiling wave induced-currents. Results show that the HADCP provides unique information on the shear in the vicinity of the rip neck, which is particularly useful for model calibration. The HADCP data was compared with local flow measurements for various tide and wave conditions, showing a very good agreement at a 5 m range. Restrictions and recommendations for HADCP implementation in the field are pointed out. The use of HADCP for horizontally profiling rip current circulations would benefit from being deployed outside of the breakers to measure the cross section of the rip head where sediment plumes and bubbles are essentially surface dominated. In this rip current system area, which would suffer from acoustic opacity only during high energy conditions, the rip current jet is strongly unstable owing to the current shear. HADCP would provide unique information on the rip current instabilities and vortex shedding in this poorly understood area of the rip current system.