Numerical Modeling of Aerosol Concentration

气溶胶浓度的数值模拟

• 批准号: 6322655
• 负责人: Michael R. Flynn
• 金额: $ 19.74万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2001
• 资助国家: 美国
• 起止时间: 2001-09-30 至 2004-09-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/6322655
• 关键词: aerosols; computer simulation; computer system design /evaluation; fluidity; model design /development; molecular size

DESCRIPTION: The long-term goal of this research is to develop a numerical algorithm for predicting the concentration and size distribution of aerosols, and to evaluate the major uncertainties in applying such a tool to occupational health problems. Solutions to current challenges such as modeling human exposure to inhalable and respirable particles, estimating the performance of size-selective aerosol samplers, and optimizing the design of ventilation systems for particulate control, are hindered by the lack of a comprehensive mathematical modeling methodology. Health effects such as chronic obstructive pulmonary disease are related to both the toxicity of the material and particle size as indicated in the size-selective sampling methodology for particles outlined in the ACGIH-Threshold Limit Value for Chemical Substances. Computational fluid dynamics (CFD) is a promising approach for these and other problems, but at present, there is not a viable method for predicting aerosol concentration fields and size distributions. There are also many sources of uncertainty in the use of CFD simulations, including the turbulence model selected, the boundary conditions imposed, and the conceptual model of reality input to the computer code. This research will: (1) provide a complimentary tool for use with CFD codes to predict aerosol concentration fields and size distributions, and (2) develop and apply a methodology to evaluate uncertainties inherent in the use of this tool for occupational and environmental exposure problems. This proposal has relevance to the NORA research priorities of: Control Technology and Personal Protective Equipment, Exposure Assessment Methods, Intervention Effectiveness, and Indoor Air. In addition it is particularly pertinent to current CDC concerns regarding the spread of infectious agents in urban (e.g., bio-terrorism), or enclosed environments (e.g., airplanes). The specific aims are to: 1) Improve our existing computer algorithm to take output from computational fluid dynamics software and make predictions of size-specific aerosol concentration fields. 2) Develop parallel implementations on large-scale machines to investigate convergence of the algorithm. 3) Assess important sources of uncertainty in the prediction of aerosol concentrations relevant to occupational health problems. These issues include, (a) time-dependent effects and turbulence in the near-wake region, (b) numerical convergence and accuracy, and (C) comparability of numerical predictions and experimental data. 4) Employ computational visualization tools to enhance interpretation of the results and to improve worker education.

描述：这项研究的长期目标是开发数值 用于预测气溶胶的浓度和尺寸分布的算法， 并评估将这种工具应用于职业的主要不确定性 健康问题。解决当前挑战的解决方案，例如建模人类 暴露于吸入和可呼吸的颗粒，估计 尺寸选择性气溶胶采样器，并优化通风设计 缺乏全面的颗粒系统系统受到阻碍 数学建模方法。诸如慢性阻塞等健康效应 肺部疾病与材料和颗粒的毒性有关 大小如颗粒的尺寸选择性采样方法中所示 在化学物质的Acgih-阈值极限值中概述。 计算流体动力学（CFD）是这些和其他的有前途的方法 问题，但目前没有可行的方法来预测气溶胶 浓度场和大小分布。也有很多来源 使用CFD模拟的不确定性，包括湍流模型 选定的边界条件和现实的概念模型 输入计算机代码。这项研究将：（1）提供免费 与CFD代码一起使用以预测气溶胶浓度和尺寸的工具 分布和（2）开发和应用一种方法来评估 使用此工具用于职业和 环境暴露问题。该提议与NORA有关 研究重点：控制技术和个人保护设备， 暴露评估方法，干预效率和室内空气。在 此外，它与当前有关CDC的关注有关 传播感染者在城市中的传播（例如生物恐怖主义）或封闭 环境（例如飞机）。具体目的是： 1）改进我们现有的计算机算法以从计算中获取输出 流体动力学软件并预测尺寸特异性气溶胶 浓度场。 2）在大型机器上开发并行实现以调查 算法的收敛性。 3）评估气溶胶预测中不确定性的重要来源 与职业健康问题有关的浓度。这些问题包括 （a）近醒区域的时间依赖性效应和湍流，（b） 数值收敛性和准确性，以及（c）数值的可比性 预测和实验数据。 4）使用计算可视化工具来增强对 结果并改善工人的教育。