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，由于意外或故意将危险物质释放到城市环境中，释放到大气中的污染物的环境和毒理学影响已成为近年来越来越重要的问题。与这个重要问题相关的主要挑战是对动态发展的流量结构与城市环境中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进行更深入的了解。与基于Reynolds平均Navier-Stokes（RANS）方法的常规方法相反，拟议的研究旨在开发新型的动态线性和非线性亚网格尺度（SGS）应力和标量 - 升华模型，用于高性能大型模拟（LES）的城市流动和分散。为了实现这项研究的目标，该提案分为两个部分。第1部分侧重于LES方法的基本方面，用于预测主动和被动标量的湍流运输；第2部分侧重于第1部分中开发的先进SGS建模方法的应用，以改善复杂城市环境中有害物质的湍流运输。为了验证本研究中开发的新型LES方法，将将获得的数值结果与实验和直接数值模拟（DNS）数据进行比较。预计拟议的研究将对现有和拟议的SGS应力和标量升级模型提供系统的比较研究。推进LE的方法论，用于对城市流量和分散的高性能计算；并导致对亚网格尺度动作的更深入的物理理解及其与城市冠层内外相干流量结构的相互作用。还可以预料，拟议的研究将为培训与机械和环境工程，高级科学计算以及国防科学技术有关的领域的高素质人员培训的机会。