波浪水槽内变水深地形上横波的运动形态与激发机理

水槽实验作为研究波浪传播变形、防波堤断面稳定性、结构动力响应等水平一维运动的重要手段，通常认为波浪在垂直于水槽的横向是保持不变的、仅沿其纵向变化。在常水深情况下，当波长与水槽宽满足一定关系时就会产生明显的横波，该现象从其发现至今已有大量研究关注。.虽然在变水深地形上的波浪传播实验中也偶有明显的横向波动现象，但通常将其归结为实验操作不当或测量误差所致。虽然也有学者采用隔板将水槽隔为两侧、在较窄一侧开展实验以消除横向波动的影响，但鲜有针对该现象的系统研究。本项目拟针对斜坡及其复合地形以及不同隆起地形这些模型实验中常见的地形，采用理论分析、模型实验与数值模拟相结合的方法，研究其上横波的运动形态，揭示地形形状与水深等参数对其影响，并基于不同波浪成份间非线性能量传递过程阐明其激发机理。本研究不仅对增进水波本质认识、提高水槽实验技术有着重要意义，还将进一步丰富非线性科学及混沌理论等相关科学的研究内涵。

Flume experiments have played a pivotal role in studying the horizontal one-dimensional motion, such as wave propagation deformation, stability of breakwater, dynamic response of structures, etc. Waves in the flume experiment are generally considered invariable transversely and only variable along the longitudinal direction. Cross waves in constant water depth can be observed when the wavelength and the width of the flume satisfy a certain relationship, and this phenomenon has been studied extensively since its discovery. Although evident transverse oscillations appear occasionally in the experiments of wave transformation over variable water depth, they are usually attributed to improper operation or measurement errors. The flume is sometimes divided into two sides, and the experiment is conducted within the narrower side to eliminate the influence of such transverse oscillations. Few studies have been published on cross waves over variable water depth..The project will focus on cross waves over the sloping beach, the composite beach and the underwater bump of different types with strategies of theoretical analysis, experiment and numerical simulation. The kinematics of cross waves will be studied, and the effect of bathymetry shape and water depth is explored. The mechanism of instability excitation is proposed by examining the nonlinear energy transfer between different wave components. This study is not only of great significance to improve the understanding the nature of water waves and flume experimental technology, but also to further expand the connotation of nonlinear science and chaos theory.