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.

集中涡流在流体力学中无处不在;例子包括龙卷风、湍流和机翼等空气动力学表面周围的流动。 因此，涡旋行为的简化模型长期以来一直被用来理解它们的基本运动和性质。 不幸的是，这些模型过于简单，无法解释许多现实世界的现象，因为它们忽略了漩涡的内部结构和与其他流动的耦合等特征。 该项目将开发新的涡流模型，其中包括这些功能，并验证他们使用的实验和数值模拟的独特组合。 最终，这些模型的目的是提供一个直观的图片涡力学，允许改进的预测和控制的流体行为在广泛的背景下。 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和增加STEM领域代表性不足的群体参与的推广计划。由于高雷诺数流动中致密涡核的普遍存在，涡力学在物理学，工程学和应用数学中得到了广泛的研究。 以前的工作涡的几何形状和拓扑结构已经表明，它是一个强大的工具，了解许多现象，在流体力学。 该项目旨在通过将核心细节和壁面/剪切相互作用纳入现有的涡丝模型，将这种分析扩展到更广泛的流动范围。 这些模型将以两种互补的方式进行验证：（1）使用流向涡脱落到管流中的实验，以及（2）对实验和简化流进行直接数值模拟，以测试模型的特定方面。 虽然研究计划将集中在一组狭窄的例子流，例子的情况下，旨在揭示涡，壁和剪切流之间的基本相互作用机制。 基于先前对孤立涡的涡的几何形状和拓扑结构的作用的研究，然后应该可以根据涡线的形状及其与背景流的对齐来研究能量、螺旋度和涡拟能等量的动力学和传输。 如果成功，这将使未来的研究更复杂的流动的许多纠缠的漩涡，大大扩大了范围的涡为基础的理解流体力学。 此外，还将开发新的数学建模工具（包括开放源代码），这些工具可应用于流体力学中的许多开放问题，如湍流转捩或龙卷风形成。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。