CAREER: Multiphase Sediment Transport Modeling Framework

为了保护国家的沿海资源免受自然灾害和人类影响，更好地了解和预测沿海沉积物运输过程的能力是很重要的。能够准确地预测大规模的沿海过程取决于对沿海发生的小规模泥沙输送的详细了解。智力优势：对大尺度海岸过程的准确预测依赖于对小尺度泥沙运移的详细了解。该项目将开发一个三维全耦合多相LES（大涡模拟）泥沙输运数值模拟框架。流体-颗粒系统的建模方法采用欧拉-欧拉两流体公式求解三维多相湍流，欧拉-拉格朗日公式进一步详细描述适合数百万泥沙颗粒的海岸泥沙输运的颗粒。新的框架解决了三维流动湍流，流体-颗粒相互作用，颗粒间应力，因此同时模拟了层载和悬浮载荷。该模型改进了现有的用于浓缩输运的Reynolds平均两相模型和用于稀流的单相3D LES模型。教育计划概述了一个职业目标，即通过发展面向少数民族的本科研究和教育计划，建立一支多元化的沿海/海洋学工作队伍。研究实习和本科水平海岸工程课程的发展将促进现有的面向研究生的海岸/海洋学专业与佛罗里达大学工程和科学本科学生之间的有效联系。更广泛的影响：为了保护国家的沿海资源免受自然灾害（如飓风）和人类影响，可靠的预测工具，允许长时间和大空间模拟沿海/河口沉积物运输过程是至关重要的。拟议的项目强调利用详细的模型来改进小规模过程的参数化，大型建模者可以进一步利用这些模型来开发与沿海规划和减灾有关的沿海/河口过程的预测工具。对于这个建立在多元文化基础上的国家来说，建立一支多元化的劳动力队伍是必不可少的。沿海/海洋学学科通常涉及减轻灾害和土地保护，以及与经济、社区和社会正义相关的问题。因此，确保沿海/海洋学专业的广泛参与尤为重要。拟议的本科研究实习（每年2名非佛罗里达大学少数民族学生和2名佛罗里达大学学生）加入并受益于现有的美国国家科学基金会在佛罗里达大学赞助的SEAGEP，该计划致力于增加少数民族学生追求学术/专业生涯的人数。面向初高中学生和教师的外联工作说明了一个基于“海岸灾害和海滩过程”的主题。它不仅可以提高环境素养，还可以作为一个渠道，向8-12年级的学生介绍一门迷人的科学/工程学科，以供他们接受高等教育。

OCE-0644497A better understanding and the ability to predict coastal sediment transport processes are important in order to preserve the nation's coastal resources from natural disasters and human impacts. Being able to accurately predict large-scale coastal processes is dependant upon on having a detailed understanding of small-scale sediment transport that takes place along the coast. Intellectual Merit: Accurate prediction of large-scale coastal processes relies on detailed understanding of small-scale sediment transport. This project will develop a 3D fullycoupled multiphase LES (Large-eddy simulation) numerical modeling framework for sediment transport. The modeling approach for fluid-particle system utilizes both Eulerian-Eulerian two-fluid formulation to resolve 3D multiphase turbulent flow and Eulerian-Lagrangian formulation for further detailed PDF description of particles that are suitable for coastal sediment transport typical of millions of sediment particles. The new framework resolves 3D flow turbulence, fluid-particle interactions, inter-granular stresses and hence concurrently models the bedload and suspended load. It improves upon existing Reynolds average two-phase models for concentrated transport and single-phased 3D LES models for dilute flow. The educational plan outlines a career goal to establish a diversified Coastal/Oceanographic work force through developing a minority-oriented undergraduate research and education program. The research internship and the development of the undergraduate-level Coastal Engineering course will facilitate effective connection between the existing graduate-oriented Coastal/Oceanographic Program and undergraduate Engineering and Science students at University of Florida (UF). Broader impact: To preserve the nation's coastal resources from natural disasters (e.g., hurricane) and human impact, reliable predictive tools that allow long-temporal and largespatialsimulation of coastal/estuarine sediment transport processes is vital. The proposed project emphasizes utilizing detailed models to provide improved parameterizations of smallscale processes that can be further utilized by large-scale modelers to develop predictive tools for coastal/estuarine processes relevant to coastal planning and hazard mitigation. Establishing a diversified work force is imperative for this country that has been built upon multiculturalism. Coastal/Oceanographic discipline often deal with hazard mitigation and land preservation, issues that are relevant to economics, communities, and social justice. Hence it is especially vital to ensure broad participation in Coastal/Oceanographic professions. The proposed undergraduate research internship (2 non-UF minority students and 2 UF students per year) joins in and benefits from the existing NSF-sponsored SEAGEP at UF that is committed to increasing the number of minority students to pursue an academic/professional career. The outreach efforts to middle/high school students and teachers illustrate a theme based on "Coastal Hazard and Beach Processes". It will not only promote environmental literacy but also serves as a conduit to introduce to 8-12 grades students a fascinating science/engineering discipline for their higher education.