Getting to the Core of Vortex Mechanics: A Hybrid Experimental and Numerical Study of Twist, Shear, and Wall Interactions

深入涡旋力学的核心：扭转、剪切和壁相互作用的混合实验和数值研究

• 批准号: 2330349
• 负责人: Dustin Kleckner
• 金额: $ 45万
• 依托单位: University of California - Merced
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2023
• 资助国家: 美国
• 起止时间: 2023-11-15 至 2026-10-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2330349&HistoricalAwards=false
• 关键词: Getting; Core; Vortex; Mechanics; Hybrid

Concentrated vortices are ubiquitous in fluid mechanics; examples include tornadoes, turbulence, and flows around aerodynamic surfaces like wings. As a result, simplified models of vortex behavior have long been used to understand their basic motion and properties. Unfortunately, these models are far too simple to explain many real-world phenomena because they neglect features like the internal structure of the vortex and coupling to other flows. This project will develop new vortex models which include these features and validate them using a unique combination of experiments and numerical simulations. Ultimately, the aim of these models is to provide an intuitive picture of vortex mechanics that allows improved prediction and control of fluid behavior in a wide range of contexts. The project also includes a significant educational component, including research opportunities for graduate and undergraduate students, as well as an outreach program designed to promote scientific education and increase participation of underrepresented groups in STEM fields.Due to the ubiquity of compact vortex cores in high Reynolds number flows, vortex mechanics is widely studied in physics, engineering, and applied mathematics. Previous work on vortex geometry and topology has shown that it is a powerful tool for understanding many phenomena in fluid mechanics. This project aims to extend this analysis to a much wider range of flows by incorporating core details and wall/shear interactions into existing vortex filament models. These models will be validated in two complementary ways: (1) experiments using streamwise vortices shed into pipe flow and (2) direct numerical simulations of the experiments and simplified flows designed to test specific aspects of the models. Although the research program will focus on a narrow set of example flows, the example cases are designed to uncover fundamental interaction mechanisms between vortices, walls, and shear flows. Building on previous research on the role of vortex geometry and topology for isolated vortices, it should then be possible to study the dynamics and transport of quantities like energy, helicity, and enstrophy in terms of the shape of the vortex lines and their alignment with respect to background flows. If successful, this will enable future studies of more complicated flows of many tangled vortices, greatly expanding the reach of a vortex-based understanding of fluid mechanics. In addition, new mathematical modeling tools (including open-source code) will be developed that could be applied to many open problems in fluid mechanics, such as the turbulent transition or tornado formation.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.

浓缩的涡旋在流体力学中无处不在。例子包括龙卷风，湍流以及翅膀等空气动力表面周围的流动。 结果，长期以来，简化的涡旋行为模型已被用来了解其基本运动和特性。 不幸的是，这些模型太简单了，无法解释许多现实现象，因为它们忽略了涡流的内部结构和耦合到其他流量之类的特征。 该项目将开发新的涡流模型，其中包括这些功能，并使用实验和数值模拟的独特组合来验证它们。 最终，这些模型的目的是提供涡流力学的直观图片，该图片允许在各种环境中改善对流体行为的预测和控制。 该项目还包括一个重要的教育组成部分，包括研究生和本科生的研究机会，以及旨在促进科学教育的外展计划，旨在提高茎领域中代表性不足的群体的参与。 先前关于涡旋几何形状和拓扑结构的工作表明，它是理解流体力学中许多现象的强大工具。 该项目旨在通过将核心细节和墙/剪切相互作用纳入现有的涡流丝模型，将此分析扩展到更广泛的流量。 这些模型将通过两种互补的方式进行验证：（1）使用流向管流中的流涡流进行实验，（2）实验的直接数值模拟和旨在测试模型特定方面的简化流量。 尽管研究计划将集中在狭窄的示例流中，但该示例案例旨在发现涡流，墙壁和剪切流之间的基本互动机制。 基于先前关于涡旋几何形状和拓扑作用的孤立涡旋的作用的研究，因此应该可以根据涡流线的形状以及它们与背景流的一致性来研究能量，螺旋和胚胎等数量的动态和运输。 如果成功，这将使未来对许多纠结涡流的更复杂的流动进行研究，从而大大扩展了基于涡流的流体力学理解。 此外，将开发新的数学建模工具（包括开源代码），可以应用于流体机制中的许多开放问题，例如湍流过渡或龙卷风组。该奖项反映了NSF的法定任务，并被认为是通过基金会的知识和更广泛影响的评估来评估通过评估的支持。