Breaking and Runup of Transient Long Waves

在2004年苏门答腊-安达曼地震和印度洋海啸之后，科学家和工程师们一直在共同努力，以提高我们对海啸流体动力学的理解，并在印度洋和南中国海建立海啸预警系统和海啸减灾计划。增强海啸数据的一个有希望的方法是分析沉积物。如果海啸沉积物可以与水深、流速、波浪特征和上升高度相关联，则可以通过测定沉积物沉积物的年代来估计过去海啸的发生时间和复发间隔。为了建立海啸水动力与大陆架和海岸带泥沙输移过程之间的关系，首先要研究波浪破碎、湍流产生/耗散、海底应力演变和瞬态长波的上升/下降流过程。根据2004年印度洋海啸期间的观测，很明显，海啸的主要波由几个（1 - 3个）破碎的长波组成。因此，本计画将进行一系列以孤立波作为海啸先导波的综合实验。主要目标是：1。识别爬高过程对波群中波数、入射波高和海滩坡度的依赖关系.量化涉及单波和多波的波浪破碎过程，主要是湍流能量和底部剪切应力和相关耗散，并探索统计稳态behavior.The更广泛的影响：这项研究是在科学和工程的几个领域之间的接口？海洋学、流体力学和海岸工程等学科之间的桥梁。详细的实验数据将为泥沙悬浮和输运模型中波浪破碎、底切应力和水流湍流的参数化提供必要的信息。因此，这项研究将对建立海啸减灾计划产生更广泛的影响。研究结果也将为今后的实验方向提供指导。该团队将继续与H教授的长期合作。德国布伦瑞克工业大学的Oumeraci和H. H.台湾国立成功大学的Hwang说。尺度效应的某些方面可以通过在他们研究所的大型波浪水槽中重复一些建议的实验条件来研究。该项目将在实验技术、数据分析和数值方法方面培训一名博士生，使他/她能够进行模型/数据比较。私家侦探在让工程系本科生参与研究和发表技术期刊论文方面有着良好的记录，本项目将在这些方面提供沿着进一步的机会。该项目还将支持一名博士后研究员，他将分担监督研究生从事该项目的责任，并将教授本科课程。

After the 2004 Sumatra-Andaman earthquake and Indian Ocean tsunami, scientists and engineers have been working together to improve our understanding of tsunami hydrodynamics and to establish early tsunami warning systems and tsunami hazard mitigation programs in the Indian Ocean and the South China Sea. A promising approach to enhance tsunami data is to analyze the sediment deposits. If tsunami deposits can be correlated with water depth, flow velocity, wave characteristics and run-up heights, the dated sediment deposits will allow estimates of times and recurrence intervals of past tsunamis. In order to establish the relation between tsunami hydrodynamics and sediment transport processes on continental shelf and coastal zones, the first step is to investigate the process of wave breaking, turbulence production/dissipation, bottom stress evolution and run-up/run-down flows of transient long waves. Based on observations during the 2004 Indian Ocean tsunami, it is evident that the leading tsunami waves consisted of several (1 -3) breaking long waves. Therefore, this project will conduct a set of comprehensive experiments in which a series of solitary waves is used as the surrogate leading tsunami waves. The principle objectives are:1. Identifying the dependence of run-up processes on the number of waves in the group, the incident wave heights, and beach slope.2. Quantifying the wave breaking processes involving single and multiple waves, primarily the turbulent energy and the bottom shear stress and associated dissipation and exploring the potential for statistically steady-state behavior.The Broader Impacts:This research is at the interface between several fields of science and engineering ? oceanography, fluid mechanics, and coastal engineering and will serve as a bridge among them. The detailed experimental data will provide the necessary information for the parameterization of wave breaking, bottom shear stress and flow turbulence in the sediment suspension and transport models. Therefore, the study will have a much broader impact on the establishment of tsunami hazard mitigation programs. The results will also provide guidance for future direction of experiments. The team will continue its long term collaborations with Prof. H. Oumeraci of the Technical University of Braunschweig, Germany and Prof. H. H. Hwang of the National Cheng Kung University, Taiwan. Certain aspects of scale effects can be investigated by repeating some of the proposed experimental conditions in the large wave flumes in their institutes. The project will train one PhD student in experimental techniques, data analysis and numerical methods so that he/she will be capable of performing model/data comparisons. The P.I. has had a good record of involving engineering undergraduate students in research and in publishing technical journal papers, and this project will provide further opportunities along those lines. The project will also support a postdoctoral researcher who will share the responsibility on supervising the graduate student working on the project and will also teach an undergraduate course.