Analysis of extreme waves based on NLSE model under background of random waves 随机波背景下基于 NLSE 模型的极端波分析

The nonlinear Schrödinger equation (NLSE) model is widely used in the study of extreme waves, and the NLSE Peregrine breathing (PB) solution has theoretically predictable spectral properties. In order to investigate whether the spectral property of the PB solution remains valid for the near-real sea state, in present paper JONSWAP random wave is introduced as a background wave. The linear superposition of the two is used to construct a superposition extreme wave model that considers random wave background. A numerical wave tank is used to simulate the evolution of the superposition wave profile. The results show that the superposition model considering the random wave component maintains the main evolutionary features of the large waves formed by the PB model, given that the background wave is not high. The random component may break the formation of extreme waves, and there is a positive correlation between the spectral predictive features and the formation of extreme waves.