Wave Breaking Across the Inner Shelf and Nearshore Regions

波浪穿过内陆架和近岸区域

• 批准号: 1435147
• 负责人: James Kirby
• 金额: $ 36.31万
• 依托单位: University of Delaware
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2018-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1435147&HistoricalAwards=false
• 关键词: Wave; Breaking; Across; Inner; Shelf

The inner shelf region, in which the wind and wave-driven upper ocean comes in contact with, and is modified by, the bottom, represents a still poorly understood region of the ocean. The region is important as a pathway for the transport of materials between the surf zone and shelf, and represents the area where surface waves begin to play a role in the mobilization and distribution of sediments. Wave breaking in this region plays an important role in momentum transfer from atmosphere to water column and likely provides a strong control on the form and strength of mean currents which would shift as the nature of breaking events changes with depth. The project will develop a variety of modeling approaches to study wave breaking in the range of depths from deep to shallow water, building on this team's recent experience in high resolution Large Eddy Simulation of breaking events in laboratory settings, and on ongoing work in developing wave resolving and wave-averaged models for dispersive wave processes. The project will also contribute to the training of a Ph.D. student and K-12 outreach activities through laboratory visits and informational scientific talks to the public, web broadcasting of public lectures, and special events at open houses at the University of Delaware.The study will focus on a transition from the topology of deep water breaking, where a vortex ring spanning the underside of the breaking event is generated, and shallow water breaking, where the breaking event is laterally bounded by regions in which vertical vortex cores ending at the surface and bottom are generated. The transition between these two topologies will be denoted as a principal demarcation between intermediate depth and shallow water behavior. In particular, the transition region represents a shift from deeper water, with breaking making a significant contribution to horizontal vorticity generation, to shallow water, where breaking primarily contributes to predominantly vertical vorticity at length scales corresponding to breaking wave crest geometries. This effort will be organized in three main topics: (1) detailed examination of breaking of finite crest lengths in a range of relative water depths spanning from deep to shallow water, using high resolution calculations based on a combined Large Eddy Simulation and Volume of Fluid model previously verified for intermediate depth breaking in wave flume experiments, (2) development of extensions to an existing non hydrostatic, wave-resolving, shock-capturing solver for surface wave breaking to improve the representation of intermediate and deep water wave breaking, for application to larger spatial scales, and (3) development of an impulsive force model for individual breaking waves, together with a stochastic formulation for the distribution of breaking events in space and time, which spans the depth range from deep to shallow water. This last model will be implemented in a non hydrostatic, wave-averaged model for use in describing wave-driven processes in the full range of water depths from shoreline to inner shelf.

内陆架区域，在那里，风和海浪驱动的上层海洋与底部接触，并被底部修改，代表了一个仍然鲜为人知的海洋区域。该区域作为海浪带和陆架之间物质运输的重要通道，代表了表面波开始在沉积物的动员和分布中发挥作用的区域。该区域的波浪破碎在动量从大气到水柱的传输中起着重要的作用，并可能对平均流的形式和强度提供强有力的控制，而平均流的形式和强度会随着破裂事件的性质随着深度的变化而变化。该项目将开发各种建模方法，以研究从深水到浅水范围内的波浪破碎，基于该团队最近在实验室环境中高分辨率大涡模拟破裂事件方面的经验，以及正在进行的开发频散波过程的波浪分辨和波浪平均模型的工作。该项目还将通过实验室访问和面向公众的信息科学讲座、公开讲座的网络广播和特拉华大学开放参观的特别活动，帮助培训一名博士生和K-12外联活动。研究将侧重于从深水破裂和浅水破裂的过渡，在深水破裂的拓扑结构中，产生一个横跨破裂事件底部的涡环，而在浅水破裂的拓扑结构中，破裂事件的横向边界是产生垂直涡核的区域。这两种地形之间的过渡将被表示为中等深度和浅水行为之间的主要分界线。特别是，过渡区代表了从深水向浅水的转变，其中破裂对水平涡度的产生做出了重大贡献，在浅水中，破裂主要导致与破裂波峰几何形状相对应的长度尺度上的垂直涡度。这项工作将分为三个主要主题：(1)使用基于大涡模拟和流体体积模型的高分辨率计算，详细研究从深水到浅水的相对水深范围内有限波峰长度的破裂，此前在波浪水槽实验中验证了中等深度破裂；(2)对现有的面波破裂的非静力、波浪分解、激波捕获解算器的扩展，以改进中深水波破裂的表示，以应用于更大的空间尺度；以及(3)开发单个破裂波的脉冲力模型，给出了破裂事件在空间和时间上分布的随机公式，其深度范围从深水到浅水。最后一个模型将在非静力、波浪平均模型中实施，用于描述从海岸线到内陆架的所有水深范围内的波浪驱动过程。