Multiphase Modelling and Experimental Characterization of Respiratory Microdroplet Suspension and Resuspension Dynamics Near Surfaces

近表面呼吸微滴悬浮和再悬浮动力学的多相建模和实验表征

基本信息

批准号：
2039310
负责人：
Anand Jagota
金额：
$ 38.11万
依托单位：
Lehigh University
依托单位国家：
美国
项目类别：
Standard Grant
财政年份：
2021
资助国家：
美国
起止时间：
2021-01-01 至 2023-12-31
项目状态：
已结题

来源：
https://www.nsf.gov/awardsearch/showAward?AWD_ID=2039310&HistoricalAwards=false
关键词：
Multiphase Modelling Experimental Characterization Respiratory

项目摘要

The main transmission routes for COVID-19 are respiratory droplets and close contact. Understanding environmental spreading pathways of COVID-19 is critical for improving safety practices. Although the flow physics of respiratory droplets at large length scales has been the focus of many studies, the microscale dynamics of the suspension behavior of individual respiratory droplets on common personal protective equipment (PPE) surfaces and the secondary exposure risk due to resuspension of those droplets have not been systematically evaluated. Initial studies show that environmental conditions such as humidity and temperature as well as surface properties, e.g. surface chemistry, roughness and wettability have significant effects on the evolution mechanism of aerosols and droplets. In particular, there is no comprehensive study on how temperature and humidity influence the aerodynamics and surface interaction of aerosols. The goal of this project is to provide fundamental understanding of the interaction between individual respiratory microdroplets and PPE surfaces under external disturbance such as body motion, through combined computational modeling and experiments. This research will help explore potential approaches that can be practiced by medical staff and general public to control motion, humidity, temperature, and surface modification that reduces aerosol-based virus spreading. The project will also incorporate research into education of undergraduate and graduate students in class, making a droplet-surface simulation tool to be made available to the research community, and outreach to K-12 and minority students.The goal of this project is to provide both a fundamental understanding of thermal-humidity-temporal microdroplet dynamics and a prediction tool for microdroplet surface interaction. The specific aims of the proposal work are to: (i) Develop a 3D multi-phase computational model for evaporation, transport, suspension, adhesion, and resuspension dynamics of respiratory droplet on various surfaces; (ii) Generate individual mimetic-virus laden respiratory microdroplets, with chemical composition and sizes similar to respiratory droplets, and investigate systematically the dynamics of the suspension and resuspension behavior of these droplets near various surfaces in a controlled environment; and (iii) Explore the effects of temperature, humidity, surface properties, and external disturbance on the suspension and resuspension behavior of droplets and suggest potential approaches for minimizing the aerosol spreading of virus. The integrated computational and experimental approach will create comprehensive understanding of the droplet-based virus transport and evolution as a function of humidity, temperature and surface characteristics.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.

COVID-19 的主要传播途径是呼吸道飞沫和密切接触。了解 COVID-19 的环境传播途径对于改进安全实践至关重要。尽管大尺度呼吸道飞沫的流动物理学一直是许多研究的焦点，但普通个人防护装备（PPE）表面上单个呼吸道飞沫悬浮行为的微观动力学以及这些飞沫重新悬浮导致的二次暴露风险尚未进行系统评估。初步研究表明，环境条件（例如湿度和温度）以及表面特性（例如表面化学、粗糙度和润湿性对气溶胶和液滴的演化机制有显着影响。特别是，目前还没有关于温度和湿度如何影响气溶胶的空气动力学和表面相互作用的全面研究。该项目的目标是通过组合计算模型和实验，对身体运动等外部干扰下个体呼吸微滴与个人防护装备表面之间的相互作用提供基本了解。这项研究将有助于探索医务人员和公众可以采用的潜在方法来控制运动、湿度、温度和表面修饰，从而减少基于气溶胶的病毒传播。该项目还将研究纳入本科生和研究生的课堂教育中，为研究界提供液滴表面模拟工具，并推广到 K-12 和少数族裔学生。该项目的目标是提供既是对热-湿度-时间微滴动力学的基本理解，也是微滴表面相互作用的预测工具。该提案工作的具体目标是： (i) 开发呼吸液滴在各种表面上的蒸发、传输、悬浮、粘附和再悬浮动力学的 3D 多相计算模型； (ii) 生成单个载有模拟病毒的呼吸道微滴，其化学成分和大小与呼吸道飞沫相似，并系统地研究这些飞沫在受控环境中靠近各种表面的悬浮和再悬浮行为的动态； (iii) 探索温度、湿度、表面特性和外部干扰对液滴悬浮和再悬浮行为的影响，并提出尽量减少病毒气溶胶传播的潜在方法。综合计算和实验方法将全面了解基于液滴的病毒传播和进化与湿度、温度和表面特征的函数关系。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值进行评估，被认为值得支持以及更广泛的影响审查标准。