Transient wave-induced instability in shallow water bottom boundary layers

浅水底部边界层瞬变波引起的不稳定

• 批准号: 0756327
• 负责人: Philip Liu
• 金额: $ 25.77万
• 依托单位: Cornell University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2008
• 资助国家: 美国
• 起止时间: 2008-07-01 至 2012-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0756327&HistoricalAwards=false
• 关键词: Transient; wave; induced; instability; shallow

CBET-0756327LiuThe 2004 Sumatra-Andaman earthquake and Indian Ocean tsunami is one of most devastating natural disasters in recent human history. After the disaster, scientists and engineers have been working together to establish an early tsunami warning system and tsunami hazard mitigation programs in the Indian Ocean region. A promising approach for improving our understanding of tsunamis is to use the deposits they create. The long term goal of our research is to relate tsunami hydrodynamics to sediment transport processes on continental shelf and coastal zone. The PIs believe that the path to reach this goal is to understand the boundary layer flow characteristics under solitary (or leading depression) waves. Recent studies on surface and internal waves show that global instabilities (a particular type of spontaneously triggered shear instability of fixed spatial extent) could occur during the flow deceleration phase at certain Reynolds numbers, leading to vortex shedding and turbulence. The PI's plan here to extend the spectral multidomain penalty method model developed by the Co-PI to further investigate the boundary layer flows under solitary (and LDN) waves in both 2D and 3D. The research activities outlined here are at the interface between several field of science and engineering- oceanography, fluid mechanics, and coastal engineering and will serve as a bridge among them. The planned research is the first phase of a long term fundamental research program, which aims at correlating the tsunami hydrodynamics with the sediment deposits left behind by the tsunamis. Dissemination during the project will be expedited by developing and maintaining a project web site, in addition to publishing in the peer-reviewed literature. The project will train one PhD student who will receive cutting-edge training in numerical methods, data analysis and analytical solution techniques. He/she will also have a solid training in experimental methods so that he/she will be capable of performing model/data comparisons. Furthermore, the student will be trained in report writing and oral presentation and he/she will be encouraged to attend technical conferences and meetings.

2004年苏门答腊-安达曼地震和印度洋海啸是人类近代史上最具破坏性的自然灾害之一。灾难发生后，科学家和工程师们一直在共同努力，在印度洋地区建立一个早期海啸预警系统和海啸减灾计划。利用海啸产生的沉积物是提高我们对海啸认识的一个有希望的方法。我们研究的长期目标是将海啸水动力学与大陆架和海岸带的沉积物输运过程联系起来。PI认为，实现这一目标的途径是了解孤立波（或领先的低压）下的边界层流动特性。最近对表面波和内波的研究表明，在一定的雷诺数下，在流动减速阶段可能发生全局不稳定性（一种特定类型的固定空间范围的自发触发剪切不稳定性），导致旋涡脱落和湍流。PI计划在此扩展Co-PI开发的谱多域罚方法模型，以进一步研究2D和3D孤立波（和LDN）下的边界层流动。这里概述的研究活动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，并将作为它们之间的桥梁。计划中的研究是一项长期基础研究计划的第一阶段，该计划旨在将海啸流体动力学与海啸留下的沉积物相关联。 除了在同行审查的文献上发表之外，还将通过开发和维持一个项目网站来加快项目期间的传播。该项目将培养一名博士生，他将接受数值方法，数据分析和分析解决方案技术方面的尖端培训。他/她还将在实验方法方面接受扎实的培训，以便他/她能够进行模型/数据比较。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。