Fluid Mechanics Research

流体力学研究

• 批准号: RGPIN-2017-03835
• 负责人: Tavoularis, Stavros
• 金额: $ 5.54万
• 依托单位: University of Ottawa
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=710575
• 关键词: Fluid; Mechanics; Research

The specific objectives of the proposed work are: a) to investigate multi-structure turbulence, to document the scaling of energy dissipation and to scrutinize the validity of fundamental assumptions in turbulence theory; b) to study the interaction between anisotropic, sheared turbulence in the free stream and turbulence generated by a stationary or moving wall; c) to document the turbulence structure, by-pass transition and relaminarisation, scalar transport from concentrated sources, heat transfer from the wall and vortex shedding from internal objects in temporally accelerating and decelerating channel flows; d) to extend Taylorian turbulent diffusion theory to developing and multi-structure flows, to devise conditions that optimize scalar diffusion and mixing and to investigate the effect of Schmidt/Prandtl number on the scalar fine structure and the development of differential diffusion; e) to study experimentally vortex stability and breakdown under the influence of transverse and streamwise disturbances, and to document in detail the mutual interactions between a streamwise vortex and coherent structures in a turbulent free stream; f) to modify an existing mock circulation loop so that it reproduces physiological coronary flows and to collect velocity measurements in an anatomical model of the aorta near the coronary inlet for different orientations of a prosthetic heart valve. Results of these research projects are expected to contribute to basic scientific knowledge in several areas of the field of fluid mechanics. Our systematic scrutiny of cornerstone assumptions in turbulence theory has the potential for a significant advance in the understanding and modelling of turbulent flows. Our measurements in many unique configurations will likely continue being benchmarks for the validation of turbulence models and CFD analyses; for example, the study of flows near moving walls would be quite relevant to the analysis of flows in turbomachinery. The study of accelerating and decelerating channel flows also has a wide range of industrial, environmental and biological applications. The work on turbulent diffusion will further contribute to our understanding and modelling capabilities of the spreading and mixing of scalar admixtures, with implications for the dispersion of pollutants and the efficiency of combustion and other chemical reactions. Our work on wing-tip vortices is important to aviation economy and safety. Finally, the work on coronary flows may assist surgeons in optimizing implantation of valves and generally help fight cardiac disease. In summary, like those of my previous work over more than four decades, the results of the proposed research should benefit the power generation, environmental, aerospace, transportation, biomedical and health services sectors of the economy, both in Canada and worldwide.

拟议工作的具体目标是：a）研究多结构湍流，记录能量耗散的尺度并审查湍流理论中基本假设的有效性； b) 研究自由流中各向异性剪切湍流与静止或移动壁产生的湍流之间的相互作用； c) 记录湍流结构、旁路转变和再层化、集中源的标量传输、壁的传热以及暂时加速和减速通道流中内部物体的涡流脱落； d) 将泰勒湍流扩散理论扩展到发展和多结构流动，设计优化标量扩散和混合的条件，并研究施密特/普朗特数对标量精细结构和微分扩散发展的影响； e) 通过实验研究横向和流向扰动影响下的涡流稳定性和破坏，并详细记录湍流自由流中流向涡流和相干结构之间的相互作用； f) 修改现有的模拟循环回路，使其再现生理冠状动脉血流，并收集冠状动脉入口附近的主动脉解剖模型中针对不同方向的人工心脏瓣膜的速度测量结果。 这些研究项目的结果预计将有助于流体力学领域多个领域的基础科学知识。我们对湍流理论中的基石假设的系统审查有可能在湍流的理解和建模方面取得重大进展。我们在许多独特配置中的测量结果可能会继续成为验证湍流模型和 CFD 分析的基准；例如，对移动壁附近的流动的研究与涡轮机械中的流动分析非常相关。加速和减速通道流的研究也具有广泛的工业、环境和生物应用。湍流扩散的工作将进一步有助于我们对标量混合物的扩散和混合的理解和建模能力，对污染物的扩散以及燃烧和其他化学反应的效率产生影响。我们在翼尖涡流方面的工作对于航空经济和安全非常重要。最后，冠状动脉血流的研究可以帮助外科医生优化瓣膜的植入，并通常有助于对抗心脏病。 总之，就像我过去四十多年来的工作一样，拟议研究的结果应该有利于加拿大和全世界的发电、环境、航空航天、交通、生物医学和健康服务经济部门。