Towards manipulating three-dimensional bluff-body wakes.

致力于操纵三维钝体尾流。

• 批准号: RGPIN-2019-04382
• 负责人: Martinuzzi, Robert
• 金额: $ 4.01万
• 依托单位: University of Calgary
• 依托单位国家: 加拿大
• 项目类别: Discovery Grants Program - Individual
• 财政年份: 2019
• 资助国家: 加拿大
• 起止时间: 2019-01-01 至 2020-12-31
• 项目状态: 已结题
• 来源: https://www.nserc-crsng.gc.ca/ase-oro/Details-Detailles_eng.asp?id=690640
• 关键词: Towards; manipulating; three; dimensional; bluff

Shifting wind patterns and gusting in the lee of buildings, ground vehicles or exposed pipelines are examples of turbulent bluff-body wakes. The flow impinges on the front of the body and detaches, or separates, along the sides resulting in reverse flow regions. The recirculating region dynamics are characterized by fluctuating velocity and pressure. The fluctuation amplitude depends on the strength and interaction of moving vortices generated in the recirculating region. These dynamics induce deleterious unsteady forces on the body, increase drag and enhance dispersion downstream. In contrast, bluff-body appendages are used in chemical reactors or combustors to enhance mixing and benefit higher product yield or cleaner combustion. Hence, the ability to manipulate bluff-body wakes to suppress or amplify dynamics is of engineering interest.*******The proposed research program is a framework for understanding and manipulating wake flows. A fundamental understanding the physics underlying the wake dynamics is to be gained. To this end, the influence of the on-coming flow and body shape on the strength of vortices and their interactions will be characterized. From this baseline, changes to the wake dynamics due to local forcing, introduced through pulsating jets along the obstacle surface, will be investigated. How these manipulations affect the unsteady forces, drag and downstream mixing will be characterized. These investigations are enabled by new techniques developed to represent and model the vortex interactions, based on compact mathematical formulations, predict the response to local forcing and optimize the manipulation parameters for suppressing or amplifying wake fluctuations. Optimization will be based on machine learning principles. These techniques are drawn from mathematics, signal processing and artificial intelligence communities, highlighting the interdisciplinary nature of this research.*******The knowledge and models developed in the program are applicable to a broad class of turbulent separated flows and thus of fundamental interest to the research community. The developed modelling techniques are relevant to industrial applications. These yield new technologies for flow monitoring and early-detection, which are suited for process control and damage mitigation for inaccessible or remote environments, such as chemical reactors and exposed pipelines. The knowledge gained in wake manipulation is anticipated to be significant for: ground transportation, reducing fuel consumption and increasing high-speed stability; and for chemical reactors or combustors, where mixing controls efficiency, product quality and yield. Compact modelling and machine learning can contribute to the design of autonomous systems. Overall, this program thus offers a context for developing skills and training highly qualified personnel for emerging technologies.***

在建筑物，地面车辆或裸露的管道的李中转移风格和阵风是湍流的悬崖体唤醒的例子。流动撞击身体的前部，并沿侧面分离或分离，导致流动区域。循环区域动力学的特征是速度和压力波动。波动幅度取决于循环区域中产生的运动涡度的强度和相互作用。这些动力学会在体内引起有害的不稳定力，从而增加拖放并增强下游的分散体。相反，化学反应器或燃烧器中使用了悬崖体的附属物，以增强混合并使更高的产品产量或更清洁的燃烧受益。因此，操纵虚张声势唤醒抑制或放大动态的能力是工程感兴趣的。*******拟议的研究计划是理解和操纵尾流流的框架。要获得尾流动力学基础的物理学的基本了解。为此，将表征在场流动和身体形状对涡流及其相互作用强度的影响。从这个基线开始，将研究由于局部强迫引起的尾流动力学的变化，该动态通过沿障碍物表面引入的脉动喷射引入。这些操作如何影响不稳定的力，拖放和下游混合。这些研究是通过基于紧凑的数学公式来代表和建模涡流相互作用的新技术来实现的，可以预测对局部强迫的响应，并优化了抑制或放大尾流波动的操纵参数。优化将基于机器学习原理。这些技术来自数学，信号处理和人工智能社区，突出了本研究的跨学科性质。开发的建模技术与工业应用有关。这些产生用于流量监测和早期检测的新技术，这些技术适用于无法接近或远程环境（例如化学反应器和暴露的管道）的过程控制和减轻损害。预计在唤醒操作中获得的知识对于：地面运输，减少燃油消耗和增加的高速稳定性；对于化学反应堆或燃烧器，混合控制效率，产品质量和产量。紧凑的建模和机器学习可以有助于自主系统的设计。总体而言，该计划为开发技能和培训高素质的人员提供了新兴技术的背景。***