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.

障碍物周围不稳定的流动是在各种物理量表中观察到的一种常见现象，从天体物理事件到微流体过程。了解不稳定的唤醒物理学可以改善车辆的设计，使它们更加高效，更稳定，例如，通过减少无人机和拖车卡车中的涡旋诱导振动。这项研究还通过提供有关建筑物周围唤醒的见解来有助于改善城市发展。拟议的研究调查了这些流的基本性质，涉及由于涡流相互作用而引起的复杂不稳定的尾流动态。我的研究将通过建模涡流相互作用对流动动力学和不稳定力变化的贡献来提高我们在尾动力学方面的知识。获得的基本知识和这里开发的工具将有助于通过识别和建模对不稳定力变化的效果最大的唤醒机制来改善车辆设计（地面，空中和水下）的长期视野。这将有助于开发新颖的流动操纵技术，这些技术激发或抑制唤醒特征，例如降低阻力变化。由于这项工作，未来的车辆将具有更高的效率和更高的稳定性，从而可以节省燃料和降低排放。除了解决不稳定涡流动力学科学中当前的知识差距外，拟议的研究还将开发新的工具，以准确，及时地建模具有现实状况的车辆周围的流量，例如高速3D湍流。该湍流模型（非线性涡流粘度模型）将是专门设计的，用于模拟具有较大曲率和压力梯度的唤醒，通常在车辆中观察到，无法使用现有模型准确有效地模拟。然后，将在尾流动力学中获得的知识将用于发展电子诱导的涡旋（EIV）作为一种新型的技术，用于在不同流中进行涡旋操纵。这是一种新的新型技术，尚未应用于大规模唤醒，例如车辆和建筑物，在微富裕设备中取得了成功。这项新技术的优势将在更长的距离和复杂条件下对流动操作进行更不可分率的控制。这里提出的研究虽然本质上是基本的，尤其是在短期内通过改进车辆的设计融合。由我的跨学科HQPS开发的工具（湍流模型），科学（不稳定涡流动力学）和技术（EIV）（EIVS）的组合将大大促进我们对不稳定的尾流动态的了解。通过减少阻力和增强的动态稳定性，这对空中和水下车辆的设计具有重大和广泛的影响。此外，这项研究旨在以对其他研究人员和行业从业人员有意义的方式识别，解释和建模数据。