Laboratory study of the nonlinear transformation of irregular waves over a mild slope |
| |
| Authors: | Bo Yu Yu-xiang Ma Xiao-zhou Ma Guo-hai Dong |
| |
| Institution: | 1. State Key Laboratory of Coastal and Offshore Engineering, Dalian University of Technology, Dalian, 116023, China
|
| |
| Abstract: | This paper considers the nonlinear transformation of irregular waves propagating over a mild slope (1:40). Two cases of irregular waves, which are mechanically generated based on JONSWAP spectra, are used for this purpose. The results indicate that the wave heights obey the Rayleigh distribution at the offshore location; however, in the shoaling region, the heights of the largest waves are underestimated by the theoretical distributions. In the surf zone, the wave heights can be approximated by the composite Weibull distribution. In addition, the nonlinear phase coupling within the irregular waves is investigated by the wavelet-based bicoherence. The bicoherence spectra reflect that the number of frequency modes participating in the phase coupling increases with the decreasing water depth, as does the degree of phase coupling. After the incipient breaking, even though the degree of phase coupling decreases, a great number of higher harmonic wave modes are also involved in nonlinear interactions. Moreover, the summed bicoherence indicates that the frequency mode related to the strongest local nonlinear interactions shifts to higher harmonics with the decreasing water depth. |
| |
| Keywords: | irregular waves shallow water nonlinear interactions wave height distribution wavelet bicoherence |
| 本文献已被 CNKI 维普 SpringerLink 等数据库收录！ |
| 点击此处可从《中国海洋工程》浏览原始摘要信息 |
| 点击此处可从《中国海洋工程》下载免费的PDF全文 |
|
