港内地形对N波诱发的港湾共振影响研究

Effect of topography inside the harbor on harbor resonance induced by N-waves

针对目前对由N波诱发的瞬变港湾共振现象的研究还极为有限,本文研究了港内折线型地形对N波诱发的瞬变港湾共振的影响。瞬变共振采用一组完全非线性Boussinesq模型-FUNWAVE-TVD-来进行模拟。使用正交模态分解法分离得到了由N波诱发的狭长型矩形港内各共振模态的响应幅值,并进而系统地研究了不同入射N波波幅和不同港内折线型地形对港内最大爬高和总波能的影响。研究表明:发现对于本文所研究的地形及入射N波波幅变化范围(0.01 m≤A0≤0.07 m),港内最大爬高随着入射N波波幅的增加而增加,随着港内平均水深的增大而减小,而折点的存在会略微降低最大爬高。总体而言,港内总波能随着平均水深的增加而呈线性增加。

As research on transient harbor resonance induced by the N-wave is very limited,the effect of broken line-type topography inside the harbor on transient harbor resonance induced by the N-wave is studied in this paper.The transient resonance is simulated by a fully nonlinear Boussinesq model,FUNWAVE-TVD.The response amplitudes of various resonant modes in the long and narrow rectangular harbor are obtained by the normal mode decomposition method.The effects of different incident N-wave amplitudes and various broken line-type topographies inside the harbor on the maximum runup and total wave energy inside the harbor are then systematically studied.Results show that for the topography studied in this paper and in the variation range of the incident N-wave amplitude(0.01 m≤A≤0.07 m),the maximum runup inside the harbor increases with increasing incident N-wave amplitude,and decreases with increasing mean depth of the water.In addition,the existence of a broken point can slightly reduce the maximum runup.In general,the total wave energy in the harbor increases linearly with increasing mean depth of the water.