实测畸形波的数值重构及机理分析

Reconstruction and mechanism analysis of measured extreme waves

为研究畸形波的生成机理,本文基于非静压模型,利用时间反转法重构2个现场测量的畸形波、新年波和Yura波,并与实测数据对比验证。通过小波分析和谐波分析方法探究其生成机理,结果表明:畸形波在传播过程中,其小波能谱的能量存在明显的聚焦-焦散变化;新年波中高阶谐波的作用最高占比为47.1%;Yura波中最高占比为30.7%;新年波和Yura波在演化过程中振幅谱存在明显变宽现象,说明新年波和Yura波是在色散聚焦、高阶谐波以及三阶共振的联合作用下形成的。在实际海况下,畸形波生成机制可能并不单一。

In this paper,we reconstructed the new year wave and Yura wave,based on the non-hydrostatic pressure model using the time-reversal method for studying the generation mechanism,and verified them by comparing with the measured data.Furthermore,wavelet analysis and harmonics analysis methods are used to researching generation mechanics,and the results show that a focused-defocused phenomenon of wavelet energy spectra existed in the evolution of new year wave and Yura wave.At the same time,the ratio of high-order harmonics effects of new year wave and Yura wave were up to 47.1%and 30.7%,respectively.Meanwhile,the amplitude spectra wave widened in the evolution of new year wave and Yura wave by analyzing wave spectra.That means dispersive focusing,higher-order harmonics and third-order waves resonance together contributed to the formation of new year wave and Yura wave.The generation mechanism of freak waves may not be single in actual conditions.