关于N波激发的港湾共振研究

Study on harbor resonance triggered by N-waves

本文采用一组完全非线性Boussinesq模型模拟了由两种不同形式的波峰在前的等边N波入射所激发的狭长矩形港内的瞬变港湾共振现象。基于正交模态分解法,定量分离了港内不同共振模态的响应幅值,并进一步系统研究了入射N波波幅和入射N波形式对港内相对波能分布的影响。研究表明,随着入射波波幅的增大,分布于高模态上的波能的比重逐渐增加,港内波能的分布趋于均匀,入射N波形式对于港内相对波能的分布也有显著影响。相比于MS形式的入射N波,TS形式的入射N波诱发的港内波能分布更加均匀。

In this paper,transient resonant phenomena inside an elongated rectangular harbor excited by two types of isosceles leading-elevation N-waves are simulated with a fully nonlinear Boussinesq model.Using a normal mode decomposition method,the response amplitudes of different resonant modes of the harbor are decomposed quantitatively.Then,the effects of the amplitude and the type of the incident N-waves on the relative wave energy distribution inside the harbor are studied systematically.It is shown that as the incident wave amplitude increases,most of the wave energy inside the harbor gradually concentrate on the higher resonant modes,and the energy distribution becomes uniform,the wave energy distribution inside the harbor is also significantly affected by the type of the N-waves.The wave energy inside the harbor excited by the TStype incident N-waves is more uniform than that excited by the MS-type N-waves.