【作者】 周妹贞；

【导师】 姚炎明；

【作者基本信息】 浙江大学 ， 港口、海岸及近海工程， 2010， 硕士

【摘要】 环流是自然界水体中广泛存在的一种水力现象,它对其所处水域的流场特性、悬移物质的输移、地形的演变、近岸生物的生长环境等有着重要的影响,因而引起了许多学者的关注,对其形成、发展及特性进行了一定的研究。本文选择了舟山六横岛附近海域作为研究海域,根据现有地形资料,结合六横近岸东北侧水域的水文实测资料,初步分析了六横近岸的环流情况。随后采用Delft-3D软件中的FLOW模块,对六横东北侧的附近水域进行了三维数值模拟,在验证良好的模型基础上,结合实测分析结果,探讨了六横近岸环流的特点。实测结果分析表明,在由小岛屿引起的切向地形突变带存在较为明显的横向环流现象,涨潮时段环流基本为顺时针方向,落潮时呈逆时针方向。水下地形突变较明显地带,环流现象也较为明显,急流时刻环流的强度大潮大于小潮,而憩流时段小潮环流的持续时间长于大潮。另外,涨急时刻在A断面近岸坡折带近底层,憩流时刻在近岸水域都存在平面环流,涨憩刻较为明显,尤其在大潮期。区域垂向环流现象不明显。数模计算结果认为：在六横近岸坡折带及由小岛屿引起的切向地形突变带存在较为明显的环流现象,它们随着水动力条件的周期性变化而生成、发展和消亡。急流时刻环流基本稳定在坡折带附近,憩流时段环流存在时间约为0.5-2小时,一般在浅水侧生成,消亡于深水侧,环流影响范围在130-700m左右；环流方向自涨潮到落潮,由顺时针方向转为逆时针方向；小潮期急流时刻流速相对较小,憩流时段环流持续时间相对较长,影响范围较大。数模结果还显示,憩流时刻,尤其是涨憩时刻,坡折带附近平面环流现象较为明显。研究水域垂向环流不明显。总体而言,由实测数据分析及三维潮流数值模拟得到的环流结果基本吻合,本文较为成功地体现了舟山六横近岸的环流现象。更多还原

【Abstract】 Natural water circulation is a common phenomenon, in which its waters flow field, suspended material transport, the evolution of topography, the near-shore environment, the growth of organisms have an important impact, which caused the concern of many scholars, they had made researches on its formation, development and characteristics.This paper chose the sea near the island of Zhoushan Liuheng as a research area, based on existing topographic data, combined with the measured data of northeast coastal waters of Liuheng, made a preliminary analysis on Liuheng circulation near the shore. FLOW module of Delft-3D software was used to calculate the 3D tidal current of Liuheng, a good model in the verification based on the combination of the measured results of the analysis of the Liuheng coastal circulation features.Measured results show that, caused by the small island with a mutation in the tangential topography there existed obvious horizontal circulation, while the clockwise circulation of flood tide, ebb tide was counterclockwise. The more obvious areas of underwater terrain mutation, circulation phenomenon is more obvious, the intensity of spring tide circulation greater than the neap tide about jet stream, while the slack flow of neap tidal circulation time longer than the spring tide. In addition, jet stream times in the A section near the bottom slope break belt, and slack times in the near-shore waters, had obvious flat circulation, especially in the spring tide period. Regional vertical circulation is not obvious.Mathematical model results that:near slope break that caused by the small island and near shore formed a obvious circulation phenomenon, they would form, develop and disappear with the change of hydrodynamic force in a tidal circle. The location of circulation were kept at slope in jet stream, while in slack flow, the time would last about 0.5-2 hours, usually formed in shallow water side of the generation, dying in the deep water side,it affected areas was about 130-700m; the circulation direction from the flood tide to ebb tide changed from clockwise to counterclockwise; neap tide moments of jet velocity is relatively small, slack flow duration is relatively long circulation time, and a larger sphere of influence. Mathematical modeling results also show that slack flow of time, especially the flood of slack time, near the slope break flat circulation phenomena are obvious. Vertical circulation of water is not obvious.Overall, the trend of the measured data analysis and numerical simulation of 3D circulation obtained results are consistent, the paper reflects the circulation phenomenon of Zhoushan Liuheng coastal successfully.更多还原