风暴潮期间底部阻力变迁及水流结构的响应

The morphology and evolution of sand ripples created by combinations of waves and currents were investigated. The effect of sand ripple dimensions and shape on bottom friction was presented to derive estimates of bottom friction. The flow structure on vegetation under wave and currents interaction was investigate to the impact of bottom friction due to vegetation on energy transmission and dissipation inside flow. The wave spectra distribution pattern was investigated to understand how vegetation causes wave energy dissipation. A bottom friction model was derived for combinations of wave, current and vegetation. A three dimensional wave-current coupled modeling system is improved and implemented to investigate wave, water level and current patterns in a region of interest during storm event . Time series of modeled storm parameters are analyzed to qualitatively describe the interaction between tide current, Ekman current, water level and typhoon-generated waves, and to understand the potential of vegetation to reducee surge levels, wave energy and inundation.

研究波流动力下沙纹形成演变物理过程，揭示波流作用下沙纹尺度形态对底部阻力的影响机制，确定不同波流组合及不同沙纹尺度形态下底部阻力；研究波流动力下植物床面水流结构分布特点，揭示植物导致的底部阻力和水流内部能量转化与耗散的关系；研究波流动力下波浪谱的分布特征，揭示波能耗散与植物特性的关系；确定不同波流组合及不同植物特性下底部阻力；完善三维风暴潮和波浪耦合数值模型，在此模拟基础上，研究风暴潮期间近岸及近海区域的波浪、水位和水流特征，分析水位、流速以及波高三者之间彼此时间过程的协同特征，揭示潮流、Ekman流、水位与台风浪之间的相互作用关系，揭示风暴潮期间植物对风暴潮和台风浪的耗散以及对风暴潮淹水的影响

通过现场实测和物理试验，研究波流作用下的沙纹边界层水动力结构，分析垂向流速剖面分布、紊动强度、雷诺应力及湍动能分布; 分析波能在沙纹表面的沿程衰减；得到纯流、纯波、波流同向和波流反向下的沙纹底床糙率。通过物理模型试验和数值模型，分析植物床面垂向流速剖面和波高沿程变化，研究波流作用下的植物床面水动力结构和阻力特性，分析波能和速度谱衰减变化规律，提出波流作用下植物阻力公式; 通过数值模型方法，建立了长江口及苏北辐射沙洲的风暴潮与波浪耦合模型，并根据试验结果改进了底床阻力模型，探讨了底床对风暴潮波浪场的影响。