Vortex Interactions and Unsteady Wake Dynamics

涡相互作用和不稳定尾流动力学

• 批准号: RGPIN-2020-03998
• 负责人: Hemmati, Arman
• 金额: $ 3.21万
• 依托单位: University of Alberta
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2021
• 资助国家: 加拿大
• 起止时间: 2021-01-01 至 2022-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=739612
• 关键词: Vortex; Interactions; Unsteady; Wake; Dynamics

Unsteady flow around obstacles is a common phenomenon observed in a variety of physical scales, from astrophysical events to microfluidic processes. Understanding the physics of unsteady wakes enables improvements in the design of vehicles, making them more efficient and stable, for example by reducing vortex induced vibrations in drones and trailer trucks. This research also contributes to improving urban development by providing insight on the wake around buildings. The proposed research investigates the fundamental nature of these flows, which involves complex unsteady wake dynamics due to vortex interactions. My research will advance our knowledge in wake dynamics by modeling the contributions of vortex interactions to flow dynamics and unsteady force variations. The fundamental knowledge gained and tools developed here will contribute to the long-term vision of improving the design of vehicles (ground, aerial and underwater) by identifying and modeling the wake mechanisms that contribute the most to unsteady force variations. This will contribute to the development of novel flow manipulation techniques that excite or suppress wake features, for example to lower drag variations. As a result of this work, future vehicles will have higher efficiency and better stability leading to fuel savings and lower emissions. Besides addressing the current knowledge gap in the science of unsteady vortex dynamics, the proposed research will develop new tools for accurate and timely modelling of flow around vehicles with realistic conditions, such as high speed 3D turbulent flow. This turbulence model (non-linear eddy viscosity model) will be specially designed for simulating wakes with large curvatures and pressure-gradients, commonly observed in vehicles, which cannot be simulated accurately and efficiently using existing models. The knowledge gained in wake dynamics will then be used to develop the concept of electromagnetically induced vortices (EIVs) as a novel technique for vortex manipulation in different flows. This is a new and novel technique that has not been applied to large-scale wakes, for example of vehicles and buildings, despite successes in micro-fluidic devices. The advantages of this new technology will be more non-intrusive control on flow manipulation over longer distances and in complex conditions. The research proposed here, although fundamental in nature, is motivated, especially in the short term, by improving the design of vehicles. The combination of tools (turbulence model), science (unsteady vortex dynamics) and technology (EIVs) developed by my multidisciplinary team of HQPs will significantly advance our knowledge of unsteady wake dynamics. This has major and broad implications in design of aerial and underwater vehicles through drag reduction and enhanced dynamic stability. Moreover, this research aims to identify, interpret and model data in a way that is meaningful to other researchers and industry practitioners.

障碍物周围的不稳定流动是在各种物理尺度（从天体物理事件到微流体过程）中观察到的常见现象，了解不稳定尾流的物理原理可以改进车辆的设计，例如通过减少引起的涡流，使车辆更加高效和稳定。这项研究还通过提供对建筑物周围尾流的洞察来促进城市发展，该研究调查了这些流动的基本性质，其中涉及由于复杂的不稳定尾流动力学。我的研究将通过模拟涡流相互作用对流动动力学和不稳定力变化的贡献来推进我们在尾流动力学方面的知识，这里获得的基础知识和开发的工具将有助于改善车辆设计的长期愿景。通过识别和建模对不稳定力变化影响最大的尾流机制，这将有助于开发激发或抑制尾流特征的新型流动操纵技术，例如降低阻力变化。这项工作的未来的车辆将具有更高的效率和更好的稳定性，从而节省燃料并降低排放，除了解决当前非定常涡流动力学科学方面的知识差距外，拟议的研究还将开发新的工具，用于在现实条件下准确、及时地建模车辆周围的流动。 ，例如高速 3D 湍流。该湍流模型（非线性涡粘模型）将专门用于模拟常见的大曲率和压力梯度尾流。无法使用现有模型准确有效地模拟车辆中的涡流，然后将使用在尾流动力学中获得的知识来开发电磁感应涡流（EIV）的概念，作为不同流中涡流操纵的新技术。尽管微流体装置取得了成功，但尚未应用于大规模尾流（例如车辆和建筑物）的新技术。这项新技术的优点是对长距离和小范围内的流量操纵进行更加非侵入性的控制。这里提出的研究虽然本质上是基础性的，但其动机是通过改进车辆的设计（湍流模型）、科学（非定常涡流动力学）和技术（EIV）来实现的。我的多学科 HQP 团队将通过减少阻力和增强动态稳定性，显着提高我们对非定常尾流动力学的认识，这对空中和水下航行器的设计具有重大而广泛的影响。一个这对其他研究人员和行业从业者有意义。