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: 2020
• 资助国家: 加拿大
• 起止时间: 2020-01-01 至 2021-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=716759
• 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.

从天体物理事件到微流体过程，围绕障碍物的非定常流动是在各种物理尺度上观察到的一种常见现象。了解非定常尾迹的物理学有助于改进车辆的设计，使其更高效、更稳定，例如通过减少无人机和拖车中涡流引起的振动。这项研究还有助于改善城市发展，为建筑物周围的尾流提供洞察力。 这项拟议的研究调查了这些流动的基本性质，这涉及到由于涡旋相互作用而产生的复杂的非定常尾迹动力学。我的研究将通过模拟涡旋相互作用对流动动力学和非定常力变化的贡献来促进我们对尾流动力学的了解。在这里获得的基本知识和开发的工具将有助于通过识别和模拟导致非定常作用力变化最大的尾流机制来改进飞行器(地面、空中和水下)的设计的长期愿景。这将有助于发展新的流动操纵技术，激发或抑制尾迹特征，例如降低阻力变化。这项工作的结果是，未来的车辆将具有更高的效率和更好的稳定性，从而节省燃料和降低排放。 除了解决目前非定常旋涡动力学科学中的知识空白之外，拟议的研究还将开发新的工具，用于准确和及时地模拟具有实际条件的车辆周围的流动，例如高速三维湍流。这种湍流模型(非线性涡粘性模型)将专门用于模拟大曲率和压力梯度的尾迹，这是在车辆中常见的，使用现有模型无法准确和有效地模拟。在尾迹动力学中获得的知识将被用来发展电磁诱导涡旋(EIV)的概念，作为一种在不同流动中操纵涡流的新技术。这是一项新的新技术，尽管在微流控设备方面取得了成功，但尚未应用于大规模的尾流，例如车辆和建筑物的尾流。这项新技术的优势将是在更长距离和复杂条件下对流量操纵进行更非侵入性的控制。 这里提出的研究，虽然本质上是基本的，但特别是在短期内，是通过改进车辆的设计来推动的。由我的HQP多学科团队开发的工具(湍流模型)、科学(非定常涡流动力学)和技术(EIV)的结合将极大地促进我们对非定常尾流动力学的了解。这对通过减阻和增强动态稳定性来设计航空和水下航行器具有重大而广泛的意义。此外，这项研究的目的是以一种对其他研究人员和行业从业者有意义的方式识别、解释和建模数据。