Unsteady Wave-Driven Circulation Cells Relevant to Rip Tides and Coastal Engineering

与激流和海岸工程相关的非定常波浪驱动环流单元

• 批准号: 0423877
• 负责人: Andrew Kennedy
• 金额: --
• 依托单位: University of Florida
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2005
• 资助国家: 美国
• 起止时间: 2005-05-01 至 2009-04-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=0423877&HistoricalAwards=false
• 关键词: Unsteady; Wave; Driven; Circulation; Cells

PROPOSAL NO.: CTS-0423877PRINCIPAL INVESTIGATOR: ANDREW B. KENNEDYINSTITUTION: UNIVERSITY OF FLORIDAUNSTEADY WAVE-DRIVEN CIRCULATION CELLS RELEVANT TO RIP TIDES AND COASTAL ENGINEERING This grant is to study wave forcing and fluctuations in irrotational and rotational wave-driven near-shore flows. The approach is primarily theoretical and numerical, but will make use of existing laboratory and field results. Field and laboratory observations have recorded significant unsteadiness in wave-driven near-shore flows with time scales much larger than a typical wave period, such a those occurring with rip tides. These fluctuations are known to be driven by some combination of unsteadiness in incident wave forcing and free instabilities of the mean flow but the relative importance of free and forced motions remains unknown. Even the relative importance of forced rotational versus irrotational fluctuations is wholly unknown. Three major tasks are stated for the study: Analytical study of wave-forced forced irrotational and rotational fluctuations; Numerical study of free and forced hydrodynamic unsteadiness in the near-shore; and Analytical study of circulation cell stability.Broader impacts of the technical proposal include understanding of near shore phenomena that lead to rip currents, which kill people every year. Besides drowning due to rip currents, understanding how flows near beaches/the shore work is important in a variety of contexts, namely beach erosion (a large sub-field of coastal engineering), transport of larval organisms (many implications for recreational and commercial fishing), and wave-driven circulation over coral reefs. Strictly focusing on beaches, there is the issue of transport of contaminants like fecal indicator bacteria that can lead to beach closures costing hundreds of millions of dollars or more every year in the US. The societal broader impacts of the proposal include wide dissemination of the results to the community and educational components, which include training of graduate students and integration of the research results into courses. This grant co-funded by the Office of Naval Research, Coastal Geosciences Program, Code 321CG.

提案编号：CTS-0423877 主要研究员：安德鲁·B·肯尼迪 机构：佛罗里达大学 与裂流和海岸工程相关的稳定波浪驱动环流单元 这笔赠款用于研究非旋转和旋转波浪驱动近岸流中的波浪强迫和波动。 该方法主要是理论和数值方法，但将利用现有的实验室和现场结果。 现场和实验室观测记录了波浪驱动的近岸流的显着不稳定性，其时间尺度远大于典型的波浪周期，例如发生激流的情况。已知这些波动是由入射波力的不稳定性和平均流的自由不稳定性的某种组合驱动的，但自由运动和受迫运动的相对重要性仍然未知。甚至强制旋转与非旋转波动的相对重要性也是完全未知的。 该研究规定了三项主要任务：波浪迫使的强迫无旋和旋转波动的分析研究；近岸自由和强迫水动力不定常的数值研究；该技术方案的更广泛影响包括了解导致每年造成人员死亡的离岸流的近岸现象。 除了因离岸流而导致溺水外，了解海滩/岸边附近的水流在各种情况下也很重要，即海滩侵蚀（海岸工程的一个大子领域）、幼虫生物的运输（对休闲和商业捕鱼的许多影响）以及珊瑚礁上波浪驱动的环流。 严格关注海滩，粪便指示细菌等污染物的运输问题可能导致美国每年导致海滩关闭，造成数亿美元甚至更多的损失。 该提案的更广泛的社会影响包括向社区和教育部门广泛传播研究结果，其中包括研究生培训以及将研究成果纳入课程。该赠款由海军研究办公室、沿海地球科学计划（代码 321CG）共同资助。