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: 2018
• 资助国家: 加拿大
• 起止时间: 2018-01-01 至 2019-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=666589
• 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）研究多结构的湍流，记录能量耗散的缩放并审查基本假设在湍流理论中的有效性； b）研究自由流中各向异性，剪切的湍流与固定壁或移动壁产生的湍流之间的相互作用； c）记录湍流结构，旁通过渡和雷米尼化，从集中源转运，从壁上传递从壁上转移和涡流从内部物体中脱落，以暂时加速和减速通道流； d）将泰勒利的湍流扩散理论扩展到发展和多结构流，以设计优化标量扩散和混合的条件，并研究Schmidt/prandtl数量对标量细胞良好结构的影响以及差分扩散的发展； e）在横向和流动干扰的影响下研究实验涡流的稳定性和分解，并详细记录湍流自由流中流向涡流与相干结构之间的相互作用； f）修改现有的模拟循环循环，以便再现生理冠状动脉流并在冠状动脉入口附近的主动脉的解剖模型中收集速度测量，以实现假肢心脏瓣膜的不同方向。 ***这些研究项目的结果有望在流体力学领域的几个领域有助于基本科学知识。我们对湍流理论中基石假设的系统审查有可能在理解和建模湍流中取得重大进步。我们在许多独特配置中的测量结果可能会继续是验证湍流模型和CFD分析的基准。例如，对移动墙附近的流量进行的研究将与涡轮机械流中的流量分析非常相关。加速和减速通道流的研究还具有广泛的工业，环境和生物学应用。关于湍流扩散的工作将进一步有助于我们对标量混合物扩散和混合的理解和建模能力，这对污染物的分散以及燃烧和其他化学反应的效率产生了影响。我们在机翼涡旋上的工作对航空经济和安全至关重要。最后，关于冠状动脉流的工作可能有助于外科医生优化瓣膜的植入，并通常有助于对抗心脏病。 总而言之，就像我以前的40多年来的工作一样，拟议的研究结果应受益于加拿大和全球的发电，环境，航空航天，运输，生物医学和卫生服务部门。