Free-surface evolution and wave kinematics for nonlinear uni-directional focused wave groups
Free-surface evolution and wave kinematics for nonlinear uni-directional focused wave groups
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非线性单向聚焦波群的自由表面演化和波运动学
DOI：
10.1016/j.oceaneng.2009.07.011
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发表时间：
2009-11-01
影响因子：
5
通讯作者：
Taylor, P. H.
中科院分区：
文献类型：
--
作者：
Ning, D. Z.;Zang, J.;Taylor, P. H.
本文讨论了瞬态波群的传播，集中在时间和空间上的一个点上，产生具有一定陡度范围的局部大波。试验研究是在大连理工大学波浪水槽中进行的。数值模拟的基础上的非线性边界积分方程求解的高阶边界元法（HOBEM）。而不是模拟整个实验槽，局部表面高程测量被用来驱动从一个点的数值解小于两个波长的焦点位置的上游，导致显着节省计算时间。在实验中测得的水面高程和水粒子运动学与波群焦点处的数值预测之间实现了极好的一致性，即使对于接近破碎的波，其陡度高达KA = 0.405，即使局部匹配的二阶理论也是不够的。线性和二阶理论的基础上的结果也提出了比较。当与一阶和二阶解相比时，完全非线性波-波相互作用产生更陡的波包络，其中中心波峰更高且更窄，而相邻的波谷更宽且更浅。(C)2009爱思唯尔有限公司版权所有。
This paper concerns the propagation of transient wave groups, focused at a point in time and space to produce locally large waves having a range of steepness. The experimental study was carried out in a wave flume at Dalian University of Technology. The numerical simulations were based on a nonlinear boundary integral equation solved by a higher-order boundary element method (HOBEM). Rather than simulate the whole experimental tank, local surface elevation measurements were used to drive the numerical solution from a point less than two wavelengths upstream of the focus position, leading to significant savings in computational time. Excellent agreement is achieved between the water surface elevations and the water particle kinematics measured in the experiments and those predicted numerically at wave group focus, even for near-breaking waves up to a steepness of kA = 0.405 for which even locally matched 2nd-order theory is inadequate. Results based on the linear and 2nd-order theory are also presented in the comparisons. When compared with the first- and 2nd-order solutions, the fully nonlinear wave-wave interactions produce a steeper wave envelope in which the central wave crest is higher and narrower, while the adjacent wave troughs are broader and less deep. (C) 2009 Elsevier Ltd. All rights reserved.