三维波生流对近岸流场结构及悬沙输运的影响研究

The wave-induced current is the key influence factor on current field and suspended sediment transport in shallow water. Based on the three-dimensional numerical model, and combined with the field observation, the three-dimensional structure of the wave-induced currents, and the influence of wave-induced currents on suspended sediment transport will be studied. By using the observed data, the three-dimensional structure change of nearshore current field under the condition of no wave and different wave will been analyzed; the current field under the action of wave, tide and wave-tide interaction will been simulated and analyzed; based on the numerical experiment, the influence factor of radiation stress will be conducted, and the influence of its vertical change on the three-dimensional structure of wave-induced current will be studied; the three-dimensional structure of wave-induced current and its influence on suspended sediment transport will be elucidated. By using the suspended sediment data, temporal and spatial distribution characteristics of suspended sediment concentration will be studied; the transport and diffusion of suspended sediment under the tide, wave-induced current and interaction will be simulated, the influence of wave and wave-induced current on suspended sediment concentration and transport will be analyzed; combined with numerical simulation of suspended sediment transport under typical wave-induced current, the effect of the three-dimensional wave-induced current structure on the longshore and offshore sediment transport will be studied; compared with the empirical formula of suspended sediment vertical distribution and longshore sediment transport rate, the influence of the three-dimensional wave-induced current structure on the plane and vertical suspended sediment transport will be analyzed.

波生流是近岸流场结构以及悬沙输运的关键影响因素。本项目基于三维数值模型，并结合现场海域观测，开展波生流的三维结构及其对悬沙输运影响的问题研究。利用观测数据分析无浪以及不同来浪下近岸流场的三维特征；模拟分析波浪、潮流以及波流共同作用下的近岸三维流场变化；基于数值实验，分析辐射应力的影响因素及其垂向变化对波生流三维结构的影响；阐明波生流的三维特征及对近岸流场结构的作用。基于实测数据分析悬沙浓度的时空分布特征；模拟近岸海域潮流、波生流作用下的悬沙输运扩散，分析波浪对悬沙浓度以及波生流对悬沙输运的影响；结合典型波生流下的悬沙输运数值实验，分析波生流的三维结构对沿岸及离岸输沙的作用；对比悬沙浓度垂向分布以及沿岸输沙率经验公式，分析近岸波流共同作用下三维波生流对平面及垂向悬沙输运的影响规律。

波生流是近岸流场结构以及悬沙输运的关键影响因素。本项目完成了现场波浪、流场的调查、观测与分析，以及近岸海域潮流及波生流的数值模拟分析工作。通过引入沿水深变化的辐射应力项，研究多种地形下的近岸波生流场的平面及三维形态特征；完成近岸波流耦合计算，分析了近岸波生流场对保守物质迁移和扩散的影响规律；通过广鹿岛沙尖子岸滩海域的资料收集及现场观测，完成了研究海域潮流场特征、年波浪特征、底质特征、悬沙变化特征、潮流与波生流耦合流场的观测与分析；基于三维波流耦合数值模型，研究了广鹿岛沙尖子海域的潮流及波生流场特征，同时数值研究了沙尖子岸滩的悬沙输移及冲淤演变规律。研究成果应用至渤海岸线修复项目中，为沙滩修复方案的设计及优化提供了支撑。