COLLABORATIVE RESEARCH: The statistical mechanics of bed load sediment transport: Scaling particle motion to fluvial form

合作研究：床载沉积物输送的统计力学：将颗粒运动缩放为河流形式

• 批准号: 1735992
• 负责人: David Furbish
• 金额: $ 22.39万
• 依托单位: Vanderbilt University
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2017
• 资助国家: 美国
• 起止时间: 2017-08-01 至 2023-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1735992&HistoricalAwards=false
• 关键词: COLLABORATIVE; RESEARCH; statistical; mechanics; bed

The streams and rivers of the United States are in a state of flux due to the building, and now decommissioning, of tens of thousands of dams, as well as changes in water use and land use influencing river flows. Extensive field studies have documented complex changes to the geometry and substrate of gravel-bedded rivers affecting fish and other biota. Due to the patchy, intermittent nature of the motion of sand and gravel carried by turbulent river flow, current models of sediment transport are unable to predict most of these critical riparian changes. This project investigates and describes sediment motion at the level of individual grains and turbulent eddies using physics-based supercomputer algorithms and advanced laboratory imaging techniques. Statistical physical principles are applied to these supercomputer and laboratory results to produce a theoretical framework that is expected to provide predictive capabilities, and thus, policy guidance regarding dramatic changes occurring in the country's waterways.The experimental work involves gravel-bed flumes and high-speed video to illustrate the basis for changes in streambed topography, and how the characteristic length-scales in this problem are determined by the distribution of particle motions. Laboratory experiments will be replicated by particle- and turbulence-resolving supercomputer simulations coupled in momentum. The work also is aimed at parameterizing statistical theory for the case of alternate bar formation, thus providing the basis for further clarifying channel-scale morphodynamics problems in which patchy, rarefied transport conditions exist.This award is cofunded by the Geomorphology and Land-use Dynamics Program and the National Strategic Computing Initiative.

由于建筑物的建筑物和现在的退役，美国的溪流和河流处于通量状态。广泛的现场研究证明了影响鱼类和其他生物群的碎石河的几何形状和基材的复杂变化。由于湍流流动的沙子和砾石运动的零碎，间歇性的性质，当前的沉积物运输模型无法预测这些关键河岸的大多数变化。该项目使用基于物理的超级计算机算法和高级实验室成像技术研究并描述了单个晶粒和湍流涡流水平的沉积物运动。统计物理原理适用于这些超级计算机和实验室结果，以产生一个理论框架，该框架有望提供预测能力，因此，有关该国水道中发生的巨大变化的政策指导。实验性工作涉及碎石层流量和高速度，以说明流水床位图的变化以及分布粒子的分布绘制的问题，以确定粒子的分布在这个问题上，这些问题是在这个问题上确定的问题。实验室实验将由粒子和湍流解析超级计算机模拟复制。这项工作还旨在针对替代条形成的统计理论进行参数化统计理论，从而为进一步阐明频道规模的形态动力学问题提供了基础，其中存在斑驳的，稀有的运输条件。该奖项由地貌学和土地使用动力学计划和国家战略计算的启发性授予。