The influence of spectral bandwidth and shape on deep-water wave breaking onset
The influence of spectral bandwidth and shape on deep-water wave breaking onset
复制标题
光谱带宽和形状对深水波浪破碎起始的影响
DOI：
10.1017/jfm.2023.766
复制
发表时间：
2023
影响因子：
3.7
通讯作者：
McAllister M
中科院分区：
文献类型：
--
作者：
McAllister M
深水表面波破碎影响着空气和海洋之间的质量、动量、能量和热量的传递。理解波浪破碎的开始时间和方式仍然是一个挑战。形成非受迫陡波的机制，即非线性或频散，被认为对波浪破碎的开始有很大的影响。在二维和深水中，光谱带宽是影响这些机制所起作用的主要因素。现有的研究中，研究了光谱带宽和波破裂开始之间的关系，提出了不同的结果，有时是相互矛盾的。为了更好地理解这种关系，我们对深水上的二维聚焦波群进行了势流模拟，目的是为了协调现有的研究。我们表明，陡度的定义方式可能是文献中混淆的主要来源。断裂起始处的局部定义的陡度作为带宽的函数而减小，而全局定义的(频谱)陡度增加。整体破裂起始陡度与光谱形状(使用参数带宽和光谱偏斜度)之间的关系太复杂了，不能用一般的方法进行参数化。然而，我们发现，我们模拟的所有光谱带宽和形状的最陡峭的不破碎波的局部表面斜率接近极限。这种基于斜率的阈值很容易测量，可以作为现有运动学断裂起始阈值的替代。基于坡度和运动学突破起始阈值之间存在潜在的联系，未来的工作应该寻求更好地理解这一点。
Deep-water surface wave breaking affects the transfer of mass, momentum, energy and heat between the air and sea. Understanding when and how the onset of wave breaking will occur remains a challenge. The mechanisms that form unforced steep waves, i.e. nonlinearity or dispersion, are thought to have a strong influence on the onset of wave breaking. In two dimensions and in deep water, spectral bandwidth is the main factor that affects the roles these mechanism play. Existing studies, in which the relationship between spectral bandwidth and wave breaking onset is investigated, present varied and sometimes conflicting results. We perform potential-flow simulations of two-dimensional focused wave groups on deep water to better understand this relationship, with the aim of reconciling existing studies. We show that the way in which steepness is defined may be the main source of confusion in the literature. Locally defined steepness at breaking onset reduces as a function of bandwidth, and globally defined (spectral) steepness increases. The relationship between global breaking onset steepness and spectral shape (using the parameters bandwidth and spectral skewness) is too complex to parameterise in a general way. However, we find that the local surface slope of maximally steep non-breaking waves, of all spectral bandwidths and shapes that we simulate, approaches a limit of . This slope-based threshold is simple to measure and may be used as an alternative to existing kinematic breaking onset thresholds. There is a potential link between slope-based and kinematic breaking onset thresholds, which future work should seek to better understand.
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影响因子：
3.7
作者：
N. Pizzo;W. Melville
通讯作者：
N. Pizzo;W. Melville
影响因子：
3.7
作者：
Deike, Luc;Popinet, Stephane;Melville, W. Kendall
通讯作者：
Melville, W. Kendall
影响因子：
4.3
作者：
Ching-Piao Tsai;D. Jeng;J. Hsu
通讯作者：
Ching-Piao Tsai;D. Jeng;J. Hsu
影响因子：
4.3
作者：
C. C. Craciunescu-C.;M. Christou
通讯作者：
C. C. Craciunescu-C.;M. Christou
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影响因子：
3.5
作者：
Pizzo, Nick;Melville, W. Kendall;Deike, Luc
通讯作者：
Deike, Luc