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.

内陆架区域是风和波浪驱动的上层海洋与底部接触并被底部改变的区域，它代表了一个仍知之甚少的海洋区域。该区域作为海浪带和陆架之间物质运输的重要通道，代表着表面波开始在沉积物的流动和分布中发挥作用的区域。该区域的波浪破碎在从大气到水柱的动量传递中起着重要作用，并且可能对平均水流的形式和强度提供强有力的控制，平均水流会随着破碎事件的性质随深度的变化而变化。该项目将开发各种建模方法来研究从深水到浅水深度范围内的波浪破碎，基于该团队最近在实验室环境中对破碎事件进行高分辨率大涡模拟的经验，以及正在开发色散波过程的波浪解析和波浪平均模型的工作。该项目还将有助于培养博士生。通过实验室参观和向公众进行信息科学讲座、公开讲座的网络广播以及特拉华大学开放日的特别活动，学生和 K-12 的外展活动。该研究将重点关注深水破碎拓扑的转变，其中产生跨越破碎事件底部的涡环，以及浅水破碎，其中破碎事件横向受到垂直涡核区域的限制 生成终止于表面和底部的。这两种拓扑之间的过渡将被表示为中深度和浅水行为之间的主要分界线。特别是，过渡区域代表从深水（破碎对水平涡流产生做出重大贡献）到浅水的转变，浅水在浅水（破碎主要在与破碎波峰几何形状相对应的长度尺度上产生主要垂直涡旋）。这项工作将分为三个主要主题：（1）详细检查从深水到浅水的一系列相对水深范围内的有限波峰长度的破裂，使用基于大涡模拟和流体体积组合模型的高分辨率计算，该模型先前在波槽实验中验证了中间深度破裂，（2）开发对现有的非静水、波浪解析、冲击捕获表面波求解器的扩展 （3）开发单个破碎波的冲击力模型，以及破碎事件在空间和时间上分布的随机公式，跨越从深水到浅水的深度范围。最后一个模型将在非静水力、波浪平均模型中实现，用于描述从海岸线到内陆架的整个水深范围内的波浪驱动过程。