Roughness Effects on Complex Near-wall Turbulent Flows

本文主要对斜肋和V型肋湍流、粗糙壁上的逆压梯度边界层和有利压力梯度边界层以及粗糙壁上的三维湍流壁射流和偏置射流进行了实验和数值研究。这些流动在许多工程系统中都有重要的应用，如热交换器、燃气轮机、分离控制、气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不足的，因为我们对这些流动中的湍流输运现象没有很好的了解。因此，我提出了一个开创性的实验研究计划，以更好地了解这些流动。我的研究团队将应用一种最先进的非侵入性技术，提供对飞机内三分量瞬时速度场的测量。然后，将使用先进的技术对这些测量结果进行后处理，以可视化涡旋结构，并探索这些结构在湍流产生和湍流传输现象中的动力学作用。我的团队还将应用计算流体力学软件和不同复杂程度的数值模型来分析这些流动。在本研究中获得的新的实验数据集将被用来评估数值结果。从这项研究中获得的基本理解和新颖的实验数据集也将使研究人员能够为不同的工程流动开发更准确的数值模型。这些精细化的数值模型将促进航空航天、供暖、通风和空调、发电以及天然气和石油行业的创新技术开发和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，与世界一流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.