Fluid Mechanics Research

提出的工作的具体目标是：a)研究多结构湍流，记录能量耗散的尺度，并仔细检查湍流理论中基本假设的有效性；B)研究自由流中的各向异性剪切湍流与静止或运动壁面产生的湍流之间的相互作用；C)记录湍流结构、旁通转换和再层化、来自集中源的标量输运、来自壁面的热量传递和来自内部物体的旋涡脱落；d)将泰勒湍流扩散理论推广到发展和多结构流动中，设计优化标量扩散和混合的条件，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)实验研究了横向扰动和流向扰动对涡旋稳定性和击穿的影响，详细记录了湍流自由流中流向涡旋和相干结构之间的相互作用；F)修改现有的模拟循环回路，使其能够再现生理冠状动脉血流，并在冠状动脉入口附近的主动脉解剖模型中收集速度测量值，用于人工心脏瓣膜的不同方向。这些研究项目的结果有望为流体力学领域的几个领域的基础科学知识作出贡献。我们对湍流理论中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下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，移动壁面附近流动的研究将与涡轮机械流动的分析非常相关。加速和减速河道流动的研究也有广泛的工业、环境和生物应用。紊流扩散方面的工作将进一步有助于我们对标量外加剂扩散和混合的理解和建模能力，对污染物的扩散、燃烧和其他化学反应的效率都有影响。翼尖涡的研究对航空经济和安全具有重要意义。最后，对冠状动脉血流的研究可以帮助外科医生优化瓣膜植入，通常有助于对抗心脏病。总之，就像我过去四十多年的工作一样，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、运输、生物医学和卫生服务等经济部门。

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.