Laboratory recreation of the Draupner wave and the role of breaking in crossing seas
Laboratory recreation of the Draupner wave and the role of breaking in crossing seas
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DOI：
10.1017/jfm.2018.886
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发表时间：
2019-02-10
影响因子：
3.7
通讯作者：
van den Bremer, T. S.
中科院分区：
文献类型：
--
作者：
McAllister, M. L.;Draycott, S.;van den Bremer, T. S.
反常波或流氓波之所以被称为反常波或流氓波，是因为它们的大小相对于它们所发生的较小波浪的总体而言出乎意料地大。25.6米高的Draupner波，在一个有意义的波高为12米的海况下观察到，是第一个确认的畸形波的现场测量之一。产生像Draupner波这样的反常波的物理机制仍然存在争议。通过在圆形波浪水槽中进行的物理实验，我们试图重现在Draupner平台测得的畸形波，并了解能够支持如此大而陡的波浪的方向条件。在这里，我们重新创建的全比例波峰振幅和轮廓的Draupner波，包括绑定设置。我们发现，波破碎的发病和类型起着重要的作用，并有显着不同的交叉和非交叉波。至关重要的是，破碎变得不那么波峰振幅限制足够大的交叉角，并涉及近垂直射流的形成。在我们的实验中，我们只能再现在Draupner平台上测量的两个波浪系统以大角度交叉的条件下的波浪的比例波峰和总波高。
Freak or rogue waves are so called because of their unexpectedly large size relative to the population of smaller waves in which they occur. The 25.6 m high Draupner wave, observed in a sea state with a significant wave height of 12 m, was one of the first confirmed field measurements of a freak wave. The physical mechanisms that give rise to freak waves such as the Draupner wave are still contentious. Through physical experiments carried out in a circular wave tank, we attempt to recreate the freak wave measured at the Draupner platform and gain an understanding of the directional conditions capable of supporting such a large and steep wave. Herein, we recreate the full scaled crest amplitude and profile of the Draupner wave, including bound set-up. We find that the onset and type of wave breaking play a significant role and differ significantly for crossing and non-crossing waves. Crucially, breaking becomes less crest-amplitude limiting for sufficiently large crossing angles and involves the formation of near-vertical jets. In our experiments, we were only able to reproduce the scaled crest and total wave height of the wave measured at the Draupner platform for conditions where two wave systems cross at a large angle.