Collaborative Research: Self-organization and transitions in anisotropic turbulence

合作研究：各向异性湍流的自组织和转变

• 批准号: 2308337
• 负责人: Edgar Knobloch
• 金额: $ 33万
• 依托单位: University of California-Berkeley
• 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: 2023-08-01 至 2026-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2308337&HistoricalAwards=false
• 关键词: Collaborative; Research; Self; organization; transitions

The impact of rotation and thermal driving on stellar and planetary bodies is clearly visible in far-field optical observations. Such observations reveal the presence of differentially rotating fluid atmospheres with embedded features in the form of large-scale eddies and jets that greatly influence the climate on the celestial body. On Earth the impact of the high latitude jet stream on weather and the destructive impact of hurricanes due to climate change is evident. Within the Jovian atmosphere, the recent discovery by the Juno mission of polar vortices illuminates the longevity of vortical structures. Theory, experimentation, and numerical simulations strongly suggest that the generation of large-scale jets and vortices is common in fluid turbulence within thin layers like the Earth’s atmosphere and on rapidly rotating celestial bodies such as Jupiter. Focusing on these paradigms, this project is dedicated to elucidating the basic mechanism behind the formation of such large-scale structures from small-scale turbulent fluctuations and its disruption via the generation of isolated, weakly-interacting, mesoscale shielded vortices, and to extending this understanding to more realistic models that introduce higher level physics such as the effects of water vapor and internal heating via latent heat release. This understanding will inform more detailed studies such as those based on realistic Global Ocean and Atmospheric Circulation Models and offers hope for understanding the conditions favoring the formation of both large-scale structures and of the smaller-scale shielded vortices. The modeling strategy taken provides a foundation upon which greater discipline-specific complexity can be built. The project will support and train one graduate student and one postdoctoral researcher in the physical understanding of energy transfer between scales in systems of geophysical relevance, asymptotic and other modeling techniques, as well as direct numerical simulations of rapidly rotating fluid layers, appropriate for planetary-scale phenomena on and within the Earth.The aim of this project is to classify different regimes of instability-driven turbulence in two dimensions (2D) as a function of the energy input and dissipation parameters, and to explore how these states evolve when three-dimensional (3D) fluctuations become increasingly important as the height of the turbulent layer increases. Particular emphasis will be placed on the recently discovered regime of shielded mesoscale vortices whose generation may disrupt the inverse energy cascade familiar from 2D turbulence with random stirring. Properties of the resulting chiral mesoscale vortex gas will be studied as a function of the layer height, as will the transition to a vortex crystal that takes place at high vortex density in 2D. The Reynolds number will be varied systematically to bridge the gap between these phenomena and related states in bacterial suspensions at low Reynolds numbers. The possibility of an analogous state in rapidly rotating 3D turbulence will be investigated in detail using a new reformulation of the Navier-Stokes fluid equations, extending direct numerical simulations to smaller Rossby numbers, together with a theoretical analysis dissecting the amplitude-phase relationships between large-scale structures and small-scale turbulence.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.

在远场观察中，旋转和热驱动对恒星和行星的影响显然是可见的在Jovian气氛中具有破坏性的有影响力的影响力身份，极地涡流的朱诺使命揭示了涡流结构的寿命，这强烈表明，大规模的喷气机和涡流很常见。诸如大气和旋转的天体之类的湍流枯萎，例如木星。扩展到引入更高级别的物理学的途中，例如基于现实的全球海洋和大气模型的水蒸气和内部热量的影响。在较小的屏蔽漩涡中，采用的建模策略可以建立IC复杂性的基础。 Ting Fluid层，适合行星尺度，在Earther中，在二维（2D）中驱动的湍流是能量和耗散参数的函数。增加。这些现象与雷诺数低的细菌悬浮液中的相关状态之间的差距将使用Navier-Stokes流体方程数的新改革进行详细研究。大规模结构与规模之间的阶段关系。该奖项反映了NSF'STUEND值得使用Toundation的知识分子CTS审查标准进行Suthy评估。