EAR-PF: The Mechanics of Turbulence and Sediment Transport: Physically-Based Numerical Modeling of Flow, Sediment and Bed Evolution in the Bedrock Canyons

EAR-PF：湍流和沉积物输送的力学：基岩峡谷中流动、沉积物和河床演化的基于物理的数值模拟

• 批准号: 1806205
• 负责人: Laura Alvarez
• 金额: $ 17.4万
• 依托单位: Alvarez Laura V
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-01-01 至 2021-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1806205&HistoricalAwards=false
• 关键词: EAR; PF; Mechanics; Turbulence; Sediment

Dr. Laura V. Alvarez has been awarded an NSF Earth Sciences Postdoctoral Fellowship to carry out a research and education plan at the University of Oklahoma and Simon Fraser University. The proposed work will make substantial contributions to our capability to numerically understand and predict the physical phenomena that control sediment transport and morphodynamic evolution of river networks. Gains in the knowledge of the role played by macro-turbulence events in sediment dynamics will allow us to obtain a deeper understanding of what determines the geomorphologic changes and will lead to the development of more efficient models.This model can also serve to investigate to what extent information obtained from well-controlled experiments and numerical simulations conducted at laboratory scale can be used to understand the physics of sediment transport at larger scales and to provide predictions about river network changes. The fellow will engage education and outreach by developing a six-week summer course in fluvial modeling, integrating many of the proposed research experiments.Eddy resolving three-dimensional simulations combined with field and laboratory observations allow elucidation of key elements of fluid dynamics and sediment transport in fluvial environments. These models can resolve the time-dependent, energetically important, turbulent structures of the flow capturing the interactions between these eddies and the loose bed boundaries where sediment entrainment and deposition can occur. This research study proposes a compelling strategy for applying state-of-the-art computational fluid mechanics to the study of sediment transport and morphodynamic processes in fluvial systems. The main objective of the proposed research is the development and testing of a fully three-dimensional turbulence resolving model using Dettached Eddy Simulation techniques that can simulate turbulent flows under a broad range of spatial and temporal scales and their effect on sediment transport, entrainment and deposition and channel/river reach evolution. The numerical model will then be used to (1) understand the role played by the plunging flows, secondary flows and velocity inversions on sediment transport, entrainment and deposition in river reaches and (2) explain morphodynamic changes based on the dynamics of the macro-turbulence effects and velocity redistribution inside the river reach.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

Laura V. Alvarez博士被授予NSF地球科学博士后奖学金，在俄克拉荷马州大学和西蒙弗雷泽大学开展研究和教育计划。拟议的工作将作出实质性的贡献，我们的能力，数值理解和预测的物理现象，控制泥沙输移和形态动力学演变的河流网络。对宏观湍流事件在沉积动力学中所起作用的认识将使我们能够更深入地了解是什么决定了地貌的变化，并将导致更有效的模型的发展。该模型还可以用于调查在多大程度上从良好的地形中获得信息。在实验室尺度上进行的受控实验和数值模拟可以用来了解更大尺度上的泥沙输运物理学，预测河网变化。该研究员将通过开发为期六周的河流建模夏季课程进行教育和宣传，整合许多拟议的研究实验，结合实地和实验室观察，涡解三维模拟可以阐明河流环境中流体动力学和沉积物输运的关键要素。这些模型可以解决时间依赖性，能量重要，湍流结构的流捕获这些涡流和松散的床边界之间的相互作用，泥沙夹带和沉积可能发生。这项研究提出了一个令人信服的战略，应用国家的最先进的计算流体力学的泥沙输运和河流系统的形态动力学过程的研究。拟议的研究的主要目标是开发和测试一个完全三维的湍流解析模型，使用分离涡模拟技术，可以模拟湍流在广泛的空间和时间尺度及其对泥沙输运，夹带和沉积和通道/河流河段演变的影响。数值模型将用于：（1）了解下伏流、二次流和速度反演对泥沙输运的作用，（2）根据宏观动力学解释了河流动力学的变化，该奖项反映了NSF的法定使命，并通过评估被认为值得支持使用基金会的知识价值和更广泛的影响审查标准。