ABSTRACT To better understand individual violent wave overtopping, of significance for coastal defence design, three breaking wave types (steep-fronted, plunging and broken) based on focused wave groups, were generated in laboratory and numerical models. High-speed video captured overtopping events and produced velocity vector maps by means of bubble image velocimetry (BIV). Results were compared with a numerical model based on a linear wave detection procedure and a two-phase incompressible Navier–Stokes-based solver. This novel approach revealed that the overtopping waves comprised an initial jet of 0.2 s duration, but dominated by quasi-steady flow. Whilst laboratory surface-elevation time-histories were highly repeatable, overtopping volume repeats were sensitive to the breaker type. Measured volumes were compared with: the numerical model (which over-predicted, but was reasonably accurate for steep-fronted waves); estimations based on BIV results (which provided very close agreement for the steep-fronted waves); and a weir-based analogy (which provided reasonable agreement, but always under-predicted).

中文翻译：

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个别剧烈的波浪翻越事件：行为和估计

摘要 为了更好地理解对海防设计具有重要意义的个别猛烈波浪越顶，在实验室和数值模型中生成了基于聚焦波群的三种破碎波类型（前倾波、下沉波和破碎波）。高速视频通过气泡图像测速法 (BIV) 捕获越过事件并生成速度矢量图。结果与基于线性波检测程序和基于两相不可压缩 Navier-Stokes 求解器的数值模型进行了比较。这种新颖的方法表明，越顶波包括持续时间为 0.2 秒的初始射流，但以准稳态流为主。虽然实验室地表高程时间历史具有高度可重复性，但超顶体积重复对破碎机类型很敏感。测量的体积与：数值模型（过度预测，但对于陡峭的前波相当准确）；基于 BIV 结果的估计（对于陡前波提供了非常接近的一致性）；和一个基于堰的类比（提供了合理的一致性，但总是被低估）。