Fate of large-scale vortices in idealized tidal lagoons
Fate of large-scale vortices in idealized tidal lagoons
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DOI：
10.1007/s10652-018-9626-4
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发表时间：
2018-09
影响因子：
2.2
通讯作者：
Carolanne V. M. Vouriot;A. Angeloudis;S. Kramer;M. Piggott
中科院分区：
文献类型：
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作者：
Carolanne V. M. Vouriot;A. Angeloudis;S. Kramer;M. Piggott
沿海和河口地区潮汐引起的涡旋的产生和演化会影响水质和沉积过程。在开发沿海水库、拦河坝和泻湖以及其他环境流应用时，必须考虑这些影响。这里给出了关于受限潮汐力域内大规模涡旋命运的结果。使用Thetis深度平均沿海海洋建模框架采用计算方法。最初，两个测试用例用于展示模型捕获振荡流道下游偶极子形成的能力。涡度和局部环流的诊断量用于跟踪二维涡旋演化和耗散。然后将该方法应用于潮汐泻湖的几何形状，其中流过入口的水流会引起一对反向旋转的涡流（偶极子）。理想化模型几何形状和入口条件用于确定三个设计参数对大型涡流结构的影响：（a）水平面中的泻湖几何纵横比，（b）入口宽度和（c）接近海岸线时的测深剖面。涡冲冲行为对无量纲比（其中是入口通道的宽度，U是最大速度，T是潮汐周期）的依赖性被重申，同时发现侧壁和倾斜测深会影响涡消散过程。
The generation and evolution of tidally-induced vortices in coastal and estuarine regions can influence water quality and sedimentary processes. These effects must be taken into consideration in the development of coastal reservoirs, barrages and lagoons, among other environmental flow applications. Results are presented here on the fate of large-scale vortices within confined tidally-forced domains. A computational approach is employed using theThetisdepth-averaged coastal ocean modeling framework. Initially, two test cases serve to demonstrate model capability in capturing the formation of dipoles downstream of oscillatory flow channels. Diagnostic quantities ofvorticityand localizedcirculationare used to track the 2-D vortex evolution and dissipation. This approach is then applied to tidal lagoon geometries, where flows through the inlet induce a pair of counter rotating vortices (dipoles). Idealized model geometries and inlet conditions are used to determine the impact of three design parameters on large-scale vortical structures: (a) the lagoon geometry aspect ratio in the horizontal plane, (b) the inlet width and (c) the bathymetry profile as the coastline is approached. The dependence of vortex flushing behavior on the dimensionless ratio(whereis the width of the inlet channel,Uis the maximum velocity andTis the tidal period) is reaffirmed, while the side walls and the sloping bathymetry are found to affect the vortex dissipation process.