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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.

新冠肺炎的主要传播途径是呼吸道飞沫和密切接触。了解新冠肺炎的环境传播途径对于改善安全做法至关重要。虽然大尺度呼吸水滴的流动物理一直是许多研究的重点，但单个呼吸水滴在普通个人防护装备(PPE)表面的悬浮行为的微观动力学以及这些水滴再悬浮造成的二次暴露风险尚未得到系统的评估。初步研究表明，环境条件(如湿度和温度)以及表面性质(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重要影响。特别是，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计算建模和实验相结合的方式，从根本上了解个体呼吸微滴与PPE表面在外部干扰(如身体运动)下的相互作用。这项研究将有助于探索医务人员和普通公众可以实践的潜在方法，以控制运动、湿度、温度和表面修饰，以减少气雾剂病毒的传播。该项目还将把研究纳入本科生和研究生的课堂教学，向研究界提供液滴-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对热-湿度-时间微滴动力学的基本理解和微滴表面相互作用的预测工具。建议工作的具体目的是：(1)建立呼吸液滴在不同表面的蒸发、传输、悬浮、附着和再悬浮动力学的三维多相计算模型；(2)产生化学成分和大小类似于呼吸液滴的单个模拟病毒的呼吸微滴，系统地研究这些液滴在受控环境中不同表面附近的悬浮和再悬浮行为的动力学；(3)探索温度、湿度、表面性质和外部扰动对液滴悬浮和再悬浮行为的影响，并提出最大限度地减少病毒气溶胶传播的潜在方法。集成的计算和实验方法将创造对基于液滴的病毒传输和进化作为湿度、温度和表面特征的函数的全面理解。这一奖项反映了NSF的法定使命，并通过使用基金会的智力优势和更广泛的影响审查标准进行评估，被认为值得支持。