Flow Visualization Study of Quantum Hydrodynamics in Superfluid Helium-4

超流 Helium-4 中量子流体动力学的流动可视化研究

• 批准号: 1807291
• 负责人: Wei Guo
• 金额: $ 33.5万
• 依托单位: Florida State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-01 至 2021-07-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1807291&HistoricalAwards=false
• 关键词: Flow; Visualization; Study; Quantum; Hydrodynamics

When liquid helium is cooled to about -271 degrees Celsius, it becomes an inviscid superfluid and can do things that other fluids cannot, such as seeping through ultra-thin cracks and climbing over container walls. The fascinating hydrodynamics of superfluid helium has many important scientific and engineering applications. For instance, it supports the most efficient heat-transport mechanism as a coolant material, and it also allows the generation of violent turbulent flows in compact laboratory equipment for model testing of airplanes and ships. However, the lack of quantitative flow measurement tools in this cold fluid has impeded progress in understanding and utilizing its hydrodynamics. In this project, the research team aims to elucidate the nature of emergent properties of various turbulent flows in superfluid helium by employing a newly developed molecular-tagging flow visualization technique. This research is expected to produce fundamental knowledge indispensable for better applications of superfluid helium. The research team is composed of graduate and undergraduate students. These students can gain experience in fluid dynamics, cryogenics, and advanced laser technologies. These skills give the students the technical dexterity necessary to excel in today's science- and technology-dominated market. In addition, the research team plans to conduct demonstrations involving superfluid helium in various educational and outreach programs at the National High Magnetic Field Laboratory to introduce profound scientific concepts to the general public.The objective of the research work is to apply a newly developed molecular tagging velocimetry (MTV) technique to tackle outstanding problems in two forms of flows in superfluid helium: thermal counterflow that can be produced by an applied heat current and quasiclassical flow that can be generated via mechanical forcing. Preliminary study on counterflow in the principle investigator's lab has revealed a novel form of turbulence. Understanding this turbulence is now regarded as one of the most challenging problems in quantum turbulence research. Using the MTV technique, the research team plans to conduct systematic study on how the energy spectrum of the counterflow turbulence may vary with heat flux in a wide range of temperatures. This information can form the base for the development of a theoretical understanding of the intriguing counterflow turbulence. In the experiment on studying towed-grid generated quasiclassical turbulence, flow visualization is combined with second sound attenuation method for probing the motion of the two fluid components in superfluid helium. The research team plans to examine the two-fluid coupling model and measure emergent flow properties that cannot be reliably determined in the past. This work is expected to pave the way for various exciting applications of superfluid helium in future turbulence research.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.

当液氦冷却到约-271摄氏度时，它变成一种无粘性的超流体，可以做其他流体做不到的事情，例如渗透超薄裂缝和爬过容器壁。超流氦令人着迷的流体动力学具有许多重要的科学和工程应用。例如，它作为冷却剂材料支持最有效的热传输机制，并且还允许在用于飞机和船舶模型测试的紧凑实验室设备中产生剧烈的湍流。然而，这种冷流体缺乏定量流量测量工具，阻碍了理解和利用其流体动力学的进展。在该项目中，研究团队旨在通过采用新开发的分子标记流可视化技术来阐明超流氦中各种湍流的涌现特性的本质。这项研究预计将为更好地应用超流氦提供不可或缺的基础知识。研究团队由研究生和本科生组成。这些学生可以获得流体动力学、低温学和先进激光技术方面的经验。这些技能为学生提供了在当今科学技术主导的市场中脱颖而出所需的技术灵活性。此外，研究团队计划在国家强磁场实验室的各种教育和推广项目中进行涉及超流氦的演示，向公众介绍深刻的科学概念。研究工作的目标是应用新开发的分子标记测速（MTV）技术解决了超流氦中两种流动形式的突出问题：可以通过施加的热流产生的热逆流和可以通过机械力产生的准经典流动。首席研究员实验室对逆流的初步研究揭示了一种新的湍流形式。理解这种湍流现在被认为是量子湍流研究中最具挑战性的问题之一。研究团队计划利用MTV技术，系统研究在较宽的温度范围内，逆流湍流的能谱如何随热通量的变化。这些信息可以为发展对有趣的逆流湍流的理论理解奠定基础。在研究拖曳网格产生的准经典湍流的实验中，将流动可视化与二次声衰减方法相结合，探测超流氦中两种流体成分的运动。研究小组计划检查二流体耦合模型并测量过去无法可靠确定的紧急流动特性。这项工作预计将为超流氦在未来湍流研究中的各种令人兴奋的应用铺平道路。该奖项反映了 NSF 的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Fully Coupled Two-Fluid Dynamics in Superfluid He4 : Anomalous Anisotropic Velocity Fluctuations in Counterflow

超流体 He4 中的完全耦合二流体动力学：逆流中的反常各向异性速度脉动

• DOI: 10.1103/physrevlett.124.155301
• 发表时间: 2020
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Yui, Satoshi;Kobayashi, Hiromichi;Tsubota, Makoto;Guo, Wei
• 通讯作者: Guo, Wei

Torque and Angular-Momentum Transfer in Merging Rotating Bose-Einstein Condensates

合并旋转玻色-爱因斯坦凝聚中的扭矩和角动量传递

• DOI: 10.1103/physrevlett.124.105302
• 发表时间: 2020
• 期刊: Physical Review Letters
• 影响因子: 8.6
• 作者: Kanai, Toshiaki;Guo, Wei;Tsubota, Makoto;Jin, Dafei
• 通讯作者: Jin, Dafei

Superdiffusion of quantized vortices uncovering scaling laws in quantum turbulence

量子化涡旋的超扩散揭示了量子湍流中的标度定律

• DOI: 10.1073/pnas.2021957118
• 发表时间: 2021
• 期刊: Proceedings of the National Academy of Sciences
• 作者: Tang, Yuan;Bao, Shiran;Guo, Wei
• 通讯作者: Guo, Wei

Molecular Tagging Velocimetry in Superfluid Helium-4: Progress, Issues, and Future Development

超流 Helium-4 中的分子标记测速：进展、问题和未来发展

• DOI: 10.1007/s10909-018-2102-1
• 发表时间: 2018
• 期刊: Journal of Low Temperature Physics
• 影响因子: 2
• 作者: Guo, Wei

Intermittency enhancement in quantum turbulence in superfluid He4

超流 He4 中量子湍流的间歇增强

• DOI: 10.1103/physrevfluids.3.094601
• 发表时间: 2018
• 期刊: Physical Review Fluids
• 影响因子: 2.7
• 作者: Varga, Emil;Gao, Jian;Guo, Wei;Skrbek, Ladislav
• 通讯作者: Skrbek, Ladislav