Modeling of Contaminant Dispersion in Complex-Terrain Flows

复杂地形流中污染物扩散的建模

• 批准号: 9708452
• 负责人: Harindra Joseph Fernando
• 金额: $ 42.5万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1997
• 资助国家: 美国
• 起止时间: 1997-08-01 至 2000-05-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=9708452&HistoricalAwards=false
• 关键词: Modeling; Contaminant; Dispersion; Complex; Terrain

ABSTRACT CTS-9708452 FERNANDO This proposal was submitted to the environmental Geochemistry and Biochemistry (EGB) solicitation NSF 96-152. The aim of this research program is to utilize the complementary expertise of laboratory experimentalists, turbulence modelers, numerical analysts and field observationalists to carry out an interdisciplinary study of air flow and pollutant dispersion, including chemical and physical transformations, in rugged (complex) terrain. As a result of restricted vertical mixing, pooling of air during nocturnal cooling and absence of background meso-scale wind flow to flush the basins, urban developments in complex terrain are prone to severe air pollution problems. Often the important surface features which influence the local wind flows are of the order of 100 meters while the valley diurnal air motions are governed by scales of more than 100 km. These scale disparities pose a difficult problem for numerical models. In addition, during morning and evening transitions from cooling to heating of the ground and vice-versa (turnover or transitional periods), wind motions are intermittent with wind speeds of the order of one meter per second, thus posing problems for field measurements. The existing models for the prediction of flow and dispersion in these areas are known to yield unsatisfactory results, especially during turnover periods. The proposed work will be directed primarily toward the development of a robust, general-purpose, geo-chemo-physical numerical model for complex-terrain flows and its validation. Laboratory and theoretical studies will be conducted to improve the fundamental understanding of and develop new parameterizations for complex-terrain, non-equilibrium turbulent flows. Detailed analyses of particle samples taken in selected field sites at 10 minute intervals will be used for the validation of turbulence parameterizations and the development of an aerosol model. An available meteorological model will be significantly m odified to incorporate these new parameterizations, including unsteady vertical mixing and aerosol transport and chemistry. This new complex-terrain model will be tested and calibrated against available and new field data. The wind fields during transitional low-wind periods will be deduced by using properly scaled laboratory complex-terrain models; a physical model of the Phoenix, Arizona area will be used for this purpose. The numerical model will be run for specific areas -- with realistic initial and boundary conditions and source distribution -- for operational forecasting of wind fields, pollutant levels, impacts on soil, interaction between indoor and outdoor air and assessment of human exposure.

摘要CTS-9708452费尔南多这项建议已提交给环境地球化学和生物化学(EGb)征集项目NSF96-152。这项研究计划的目的是利用实验室实验员、湍流模型师、数值分析员和现场观测员的互补专业知识，对崎岖(复杂)地形中的空气流动和污染物扩散进行跨学科研究，包括化学和物理变化。由于垂直混合受到限制，夜间降温时空气聚集，以及没有背景中尺度风流冲刷盆地，复杂地形的城市发展容易出现严重的空气污染问题。影响当地风流的重要地物往往在100米量级，而山谷的日空气运动则受100公里以上尺度的控制。这些尺度上的差异给数值模型带来了难题。此外，在地面从冷却到加热的早晚过渡期间(周转或过渡期)，风的运动是间歇性的，风速约为每秒一米，因此给现场测量带来了问题。已知现有的预测这些地区的流动和扩散的模型产生的结果并不令人满意，特别是在周转期。拟议的工作将主要针对开发一个健壮的、通用的、复杂地形流动的地球化学物理数值模型及其验证。将进行实验室和理论研究，以提高对复杂地形、非平衡湍流的基本理解并开发新的参数化。将对选定现场每隔10分钟采集一次的颗粒样本进行详细分析，以验证湍流参数和开发气溶胶模型。将对现有的气象模式进行重大修改，以纳入这些新的参数化，包括非稳定的垂直混合以及气溶胶输送和化学。这一新的复杂地形模型将根据现有的和新的现场数据进行测试和校准。过渡低风期间的风场将通过使用适当比例的实验室复杂地形模型来推导；为此将使用亚利桑那州凤凰城地区的物理模型。数值模式将在特定地区运行--具有现实的初始和边界条件以及源分布--用于风场、污染物水平、对土壤的影响、室内和室外空气之间的相互作用以及人类暴露的评估的业务预报。