Evolution of a Random Directional Wave and Freak Wave Occurrence
Evolution of a Random Directional Wave and Freak Wave Occurrence
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DOI：
10.1175/2008jpo4031.1
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发表时间：
2009-03
影响因子：
3.5
通讯作者：
T. Waseda;T. Kinoshita;H. Tamura
中科院分区：
文献类型：
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作者：
T. Waseda;T. Kinoshita;H. Tamura
摘要利用定向波发生器，在实验室波浪水槽（长50 m，宽10 m，深5 m）中研究了深水中随机定向波的演变。进行了一些实验，改变了各种频谱参数（波陡0.05 < e < 0.11，方向扩展高达36°，频率带宽0.2 < δk/k < 0.6）。波浪的演变研究了一个阵列的波线分布在坦克。当谱参数改变时，波高统计量也随之改变。在没有任何波的方向性的情况下，由于准共振波-波相互作用，超过有效波高两倍的波（畸形波）的出现随着频率带宽变窄和陡度增加而增加。然而，极端波的概率随着定向带宽的加宽而迅速降低。引入了有效Benjamin-Feir指数（BFIeff），扩展了BFI（非线性和色散的相对大小），以包含非线性和色散的影响。
Abstract The evolution of a random directional wave in deep water was studied in a laboratory wave tank (50 m long, 10 m wide, 5 m deep) utilizing a directional wave generator. A number of experiments were conducted, changing the various spectral parameters (wave steepness 0.05 < e < 0.11, with directional spreading up to 36° and frequency bandwidth 0.2 < δk/k < 0.6). The wave evolution was studied by an array of wave wires distributed down the tank. As the spectral parameters were altered, the wave height statistics change. Without any wave directionality, the occurrence of waves exceeding twice the significant wave height (the freak wave) increases as the frequency bandwidth narrows and steepness increases, due to quasi-resonant wave–wave interaction. However, the probability of an extreme wave rapidly reduces as the directional bandwidth broadens. The effective Benjamin–Feir index (BFIeff) is introduced, extending the BFI (the relative magnitude of nonlinearity and dispersion) to incorporate the effect...