Interactions between Long Ocean Waves and Muddy Sea Floor

知识价值：在大陆架和沿海地区，风浪与海底相互作用，并发生了许多动态过程。如果海底是由沉积物组成的，那么与沉积物流变有关的各种耗散机制在增强波浪阻尼和改变波浪特性方面起着重要作用。在这个项目下，研究者将进行一个综合的理论和实验计划，以完成几个科学目标。首先，将开发瞬态波荷载下泥浆流的解析解，以提高我们对各种海底耗散机制及其对瞬态长波传播的影响的基本理解。其次，将生成一个高质量的详细实验数据集档案，研究人员可以使用这些数据集来测试他们自己的分析和数值模型。第三，将进行模型-数据比较，以了解解析解的局限性，并将开发波浪荷载下泥浆流动的直接数值模拟（DNS）模型，以进一步探索物理过程。针对各种波浪载荷，将开发具有不同应力-应变关系的Navier-Stokes解算器，该解算器取决于流体泥浆的流变特性。第四，将发展包含海底耗散机制的深度积分、相位分辨波传播模型。计划进行一项个案研究，以检查圭亚那海岸系统的波衰减，该系统的特点是亚马逊河泥的沉积物非常厚。更广泛的影响：拟议的研究活动是在科学和工程的几个领域之间的界面——海洋学、流体力学和海岸工程，并将成为它们之间的桥梁。该项目将培养一名博士生，该博士生将接受实验技术、数值方法和解析解技术方面的前沿培训。此外，学生将接受报告写作和口头陈述的培训，并鼓励他/她参加技术会议和会议。本项目所开发的DNS数值模型将成为许多相关工程科学领域的研究工具，并可在经过一些修改后用于研究波浪引起的土壤破坏、泥石流和海岸建筑物周围的冲刷。考虑海底耗散机制的boussinesq型波浪模型是该项目的主要产品，将成为沿海工程师在存在泥泞海床的沿海地区的各种应用中的有用工具。新的boussinesq型模型也可用于研究海啸期间沉积物的搬运和沉积。实验室数据将用于当前和其他开发下的其他数值模型的基准。为了加快传播在项目中所学到的知识，我们将开发和维护一个项目网站，并在同行评审的文献中发表手稿。研究者的大部分研究活动可以在以下网页上找到：http://ceeserver.cee.cornell.edu/pll-group/index.htm康奈尔大学的一些高级本科生和研究生课程将从该研究项目中受益匪浅，因为该项目开发的实验室测量技术可以用于这些课程。目前，研究者正在指导3名由美国国家科学基金会和工程学院基金资助的REU学生。在该项目中，他将继承这一传统，鼓励感兴趣的本科生参与研究。

Intellectual Merit: On the continental shelf and in the coastal zone, wind waves interact with sea floor and a number of dynamic processes take place. If the sea floor is composed of sediments, a variety of dissipation mechanisms associated with the sediment rheology play important roles in enhancing wave damping and in modifying wave characteristics. Under this project the investigator will conduct an integrated theoretical and experimental program to accomplish several scientific goals. First, analytical solutions for mud flows under transient wave loadings will be developed to improve our fundamental understanding of various sea bottom dissipative mechanisms and their impacts on transient long wave propagation. Second, An archive of quality detailed experimental data sets that researchers may use to test their own analytic and numerical models will be generated. Third, model-data comparisons will be performed to understand the limitations of analytical solutions and direct numerical simulation (DNS) models for mud flows under wave loadings will be developed to further explore the physical processes. A Navier-Stokes solver with different stress-strain relationships, which depend on the rheology of the fluid mud, will be developed for various wave loadings. Fourth, depth-integrated, phase-resolving wave propagation models with sea bottom dissipative mechanisms included will be developed. A case study is planned to examine the wave attenuation in the Guyana coastal system that is characterized by very thick deposits of Amazon mud.Broader Impacts: The proposed research activities are at the interface between several field of science and engineering ¨C oceanography, fluid mechanics, and coastal engineering and will serve a bridge among them. The project will train one PhD student who will receive cutting edge training in experimental techniques, numerical methods and analytical solution techniques. Furthermore, the student will be trained in report writing and oral presentation and he/she will be encouraged to attend technical conferences and meetings. The DNS numerical models to be developed in the proposed project will be useful as research tools for many related engineering science field and can be employed after some modifications to investigate wave©\induced soil failures, debris flows and scouring around coastal structures. The Boussinesq-type wave models with the seafloor dissipative mechanisms considered, which are the main products of the project, will be useful tools for coastal engineers in various applications in the coastal regions where muddy seabeds are present. The new Boussinesq-type model can also be used to investigate the sediment transport and deposit during tsunamis. The laboratory data will be used to benchmark other numerical models under current and other development. To expedite the dissemination of what is learned during the project, we will develop and maintain a project web site, in addition to publishing manuscripts in the peer-reviewed literatures. Most of the investigator¡¯s research activities can be found on the following webpage: http://ceeserver.cee.cornell.edu/pll-group/index.htm Several upper-level undergraduate and graduate student courses at Cornell will be benefit significantly from the research project, as the laboratory measurement techniques developed in the project can be used in these courses. Currently the investigator is supervising 3 REU students supported by NSF and Engineering College fund. In the proposed project, he will carry on this tradition and encourage interested undergraduates to participate in research.