Collaborative Research: Advancing turbidity currents: moving sources, polydispersity and aggregation

合作研究：推进浊流：移动源、多分散性和聚集

基本信息

批准号：
2138583
负责人：
Eckart Meiburg
金额：
$ 22.5万
依托单位：
University of California-Santa Barbara
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2022
资助国家：
美国
起止时间：
2022-02-01 至 2024-09-30
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2138583&HistoricalAwards=false
关键词：
Collaborative Research Advancing turbidity currents

项目摘要

Gravity currents are mostly horizontal flows that are driven by density variations in a fluid or by density differences between two fluids. They play a central role in the transport of sediment in lakes, rivers, and oceans, and they are also important in emerging and potentially transformative technologies such as deep-sea mining and geoengineering. Despite a rich history of research on gravity currents, some fundamental scenarios have yet to be explored or remain substantially unresolved. This collaborative project will integrate analytical modeling, numerical simulation and laboratory experimentation with a unique field experimental data set to advance understanding of particle-laden gravity currents. This project has potential for transformative impacts by informing environmental regulations for such emerging industries as deep-sea mining. Deep-sea mining is expected to re-suspend large volumes of sediment in the pristine abyssal ocean environment, and the knowledge and models developed through this project will provide the toolbox needed to assess the evolution of these sediment plumes. The project will provide training for university students at all academic levels and for high-school students who will participate in the project through established programs at MIT and UCSB. The project is divided into three interconnected topics. The first concerns the evolution of gravity and particle-driven currents released from a moving source. The goals are to understand how the ratio of source speed to buoyancy velocity influences the dynamics of the current, investigate the role of background current, and develop empirical models that predict transport processes. The second point of focus is to quantify sediment detrainment from polydisperse particle-driven currents and determine its sensitivity to the particle size and velocity distribution through concurrent laboratory experiments and numerical simulations. Empirical models of polydisperse particle-driven currents will be extended to include entrainment and detrainment and incorporated into the moving source gravity current model. Finally, the role of flocculation and aggregation of particles on the propagation of polydisperse particle-driven currents will be experimentally investigated by systematically varying the sediment’s history, with the goal of developing macroscale numerical models for flocculation and integrating the findings into the moving source model.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.

重力流主要是由流体中的密度变化或两种流体之间的密度差驱动的水平流，它们在湖泊、河流和海洋中的沉积物输送中发挥着核心作用，并且它们对于新兴和潜在的沉积物也很重要。尽管对重力流的研究有着丰富的历史，但一些基本场景尚未得到探索或仍未得到解决，该合作项目将把分析建模、数值模拟和实验室实验结合起来。独特领域该项目通过为深海采矿等新兴行业的环境法规提供信息，预计将重新悬浮大量沉积物，从而促进对充满颗粒的重力流的理解。原始的深海海洋环境，通过该项目开发的知识和模型将提供评估这些沉积物羽流演变所需的工具箱。该项目将为所有学术水平的大学生和参加该项目的高中生提供培训。该项目通过麻省理工学院和加州大学圣巴巴拉分校的既定项目，该项目分为三个相互关联的主题，第一个主题涉及移动源释放的重力和粒子驱动电流的演变，目标是了解源速度与浮力速度的比率如何影响。第二个重点是量化多分散颗粒驱动流的沉积物脱失，并通过确定其对颗粒尺寸和速度分布的敏感性。并行实验室实验和数值模拟多分散颗粒驱动流的经验模型将扩展到包括夹带和脱滞，并纳入移动源重力流模型中，最后，将通过实验对颗粒的絮凝和聚集的作用进行实验。通过系统地改变沉积物的历史进行研究，目标是开发宏观反映絮凝的数值模型，并将研究结果整合到移动源模型中。该奖项授予 NSF 的法定使命和通过使用基金会的智力优点和更广泛的影响审查标准进行评估，该项目被认为值得支持。