Roughness Effects on Complex Near-wall Turbulent Flows

本文的研究重点是斜肋和V形紊流器上的湍流流动、粗糙壁面上的逆压梯度边界层和有利压力梯度边界层以及粗糙壁面上的三维湍流壁面射流和偏置射流的实验和数值研究。这些流在许多工程系统中有重要的应用，如热交换器、燃气轮机、分离控制、膜冷却技术以及加热、通风和空调。我们准确预测这些流动的能力是有缺陷的，因为这些流动中的湍流输运现象还没有得到很好的理解。因此，我提出了一个开创性的实验研究计划，以更好地理解这些流动。我的研究团队将采用一种最先进的非侵入式技术来测量平面上的瞬时三分量速度场。然后将采用先进的技术对这些测量进行后处理，以可视化旋涡结构，并探索这些结构在湍流产生和湍流传输现象中的动态作用。我的团队还将应用计算流体动力学软件和不同复杂程度的数值模型来分析这些流动。本研究获得的新实验数据集将用于评估数值结果。从这项研究中获得的基本理解和新的实验数据集也将使研究人员能够为不同的工程流程开发更准确的数值模型。这些精细化的数值模型将促进创新技术的发展，以及在航空航天、供暖、通风和空调、发电、天然气和石油工业中高效环保工程系统的设计。这将为加拿大创造巨大的社会经济效益。该项目还将创造一个真正特殊的环境，与世界级的湍流建模专家开展战略研究合作，并指导下一代高素质的工程师、研究人员和教授。

The proposed research focuses on experimental and numerical study of turbulent flows over inclined and V shaped rib turbulators, adverse and favorable pressure gradient boundary layers over rough walls, and three-dimensional turbulent wall jets and offset jets over rough walls. These flows have important applications in a multitude of engineering systems such as heat exchangers, gas turbines, separation control, film cooling technology as well as heating, ventilation, and air conditioning. Our ability to accurately predict these flows is deficient because the turbulent transport phenomena in these flows are not well understood. Therefore, I am proposing a seminal experimental research program to provide a better understanding of these flows. My research team will apply a state-of-the-art non-intrusive technique that will provide measurements of the instantaneous three-component velocity field in a plane. Advanced techniques will then be employed to post-process these measurements to visualize the vortical structure and explore the dynamic roles of these structures in turbulence production and turbulent transport phenomena. My team will also apply computational fluid dynamics software and numerical models with varying sophistication to analyze these flows. The novel experimental datasets obtained in this research will be used to evaluate the numerical results. The fundamental understanding gained from this research and the novel experimental data sets will also enable researchers to develop more accurate numerical models for diverse engineering flows. These refined numerical models will facilitate the development of innovative technologies and design of efficient and environmentally friendly engineering systems in the aerospace, heating, ventilation, and air conditioning, power generation and gas and oil industries. This will create huge socio-economic benefit for Canada. This project will also create a truly exceptional environment to develop strategic research collaboration with world class experts in turbulence modeling and mentor the next generation of highly qualified engineers, researchers and professors.