Novel subgrid-scale modelling for large-eddy simulation of turbulent flow and dispersion in urban environments

用于城市环境中湍流和扩散的大涡模拟的新型亚网格尺度建模

• 批准号: 357453-2008
• 负责人: Wang, BingChen
• 金额: $ 1.66万
• 依托单位: University of Manitoba
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2011
• 资助国家: 加拿大
• 起止时间: 2011-01-01 至 2012-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=483116
• 关键词: Novel; subgrid; scale; modelling; large

The environmental and toxicological impact of the downwind dispersion of contaminants released into the atmosphere, resulting from an accidental or deliberate release of a hazardous material into an urban environment, has become an increasingly important problem in recent years. The major challenge associated with this important problem involves obtaining a deeper understanding of the interaction of the dynamically evolving flow structures with the complex building geometry in an urban environment, as well as the coupling of the momentum, thermal energy and passive scalar transport processes. In contrast to conventional methods based on the Reynolds averaged Navier-Stokes (RANS) approach, the proposed research aims at developing novel dynamic linear and nonlinear subgrid-scale (SGS) stress and scalar-flux models for high-performance large-eddy simulation (LES) of urban flow and dispersion. In order to achieve the goal of this research, this proposal is divided into two parts. Part 1 focuses on the fundamental aspects of the LES methodology for prediction of turbulent transport of active and passive scalars; and Part 2 focuses on application of the advanced SGS modelling approaches developed in Part 1 for improved LES of turbulent transport of hazardous substances in complex urban environments. In order to validate the novel LES approaches developed in this research, the obtained numerical results will be compared with experimental and direct numerical simulation (DNS) data. It is anticipated that the proposed research will provide a systematic comparative study of the existing and proposed SGS stress and scalar-flux models; advance the methodology of LES for high-performance computing of urban flow and dispersion; and lead to a deeper physical understanding of the subgrid-scale motions and their interactions with the coherent flow structures within and above the urban canopy. It is also anticipated that the proposed research will provide an opportunity to train highly qualified personnel in areas related to mechanical and environmental engineering, advanced scientific computing, and defence science and technology.

近年来，由于意外或故意将有害物质释放到城市环境中而导致释放到大气中的污染物顺风扩散，其对环境和毒理学的影响已成为一个日益重要的问题。与这一重要问题相关的主要挑战包括更深入地了解城市环境中动态演变的流动结构与复杂建筑几何形状的相互作用，以及动量、热能和被动标量传输过程的耦合。与基于雷诺平均纳维斯托克斯（RANS）方法的传统方法相比，本研究旨在开发新型动态线性和非线性亚网格尺度（SGS）应力和标量通量模型，用于高性能大涡模拟（ LES）城市流动和分散。为了实现本研究的目标，本提案分为两部分。第 1 部分重点介绍 LES 方法的基本方面，用于预测主动和被动标量的湍流传输；第 2 部分重点介绍第 1 部分中开发的先进 SGS 建模方法的应用，以改进复杂城市环境中危险物质湍流传输的 LES。为了验证本研究中开发的新型 LES 方法，获得的数值结果将与实验数据和直接数值模拟 (DNS) 数据进行比较。预计拟议的研究将为现有和拟议的 SGS 应力和标量通量模型提供系统的比较研究；推进 LES 方法用于城市流量和扩散的高性能计算；并导致对次网格尺度运动及其与城市冠层内部和上方的相干流动结构的相互作用有更深入的物理理解。预计拟议的研究将为机械和环境工程、先进科学计算以及国防科学技术相关领域培养高素质人才提供机会。