CDS&E: Feedback of energetic particles on plasma turbulence

CDS

• 批准号: 1907876
• 负责人: Jane Pratt
• 金额: $ 39.68万
• 依托单位: Georgia State University Research Foundation, Inc.
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-07-15 至 2025-06-30
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1907876&HistoricalAwards=false
• 关键词: CDS&E; Feedback; energetic; particles; plasma

This project will develop a new computational framework for modeling astrophysical sources of high energy particles. In space, the vast majority of visible matter consists of hot charged gas, called plasma. Astrophysical flows of plasma can move very fast, become turbulent, and generate shock waves. This kind of plasma turbulence is key to a broad range of space and astrophysical problems, including black-hole accretion disks, supernova explosions, star formation, and even space weather. Some of the particles in a turbulent plasma gain enormous amounts of energy by interacting with the turbulent motions, and with shock waves. In different settings, these particles may be called cosmic rays, solar energetic particles, or pick-up ions. While these particles gain energy, they also change the structure of the shock waves, and the fundamental characteristics of the turbulence. In this project a new theoretical model for this interaction will be developed by extending a theoretical framework that has been successfully used to model particle interactions for turbulent combustion in car engines. State-of-the-art simulations will be produced to examine how energetic particles can modify plasma turbulence and shocks. These simulations will provide detailed understanding of how energetic particles move through an astrophysical plasma, and may have a practical impact on improving space weather prediction to help minimize satellite radiation damage. This project will also support efforts to increase diversity among students and professionals in high performance computing.Plasma turbulence and instabilities play a fundamental role in accelerating particles to high energies. As particles gain energy, they interact with the plasma surrounding them, resonating with certain types of plasma waves to stabilize them while destabilizing others, and changing the character of the background turbulence in ways that have not been fully quantified or understood. This interaction with the turbulent background plasma is key to the acceleration of many types of energetic particles including high-energy cosmic rays, solar energetic particles, and pick-up ions. In this project, a new computational model and tool for simulating multi-species compressible plasma turbulence will be produced by expanding on a state-of-the-art model for multi-component turbulent engineering flows and combustion. This model will self-consistently include the energetic particle feedback on the plasma. The main focus of this project is to produce high-quality simulations of the shock structure and surrounding turbulence as they are modified by energetic particles. This will address several open questions: (1) How do energetic particles alter turbulence around a shock? (2) How do energetic particles alter the magnetic field and magnetic instabilities around a shock? (3) How do modifications to shocks, turbulence, and magnetic instabilities contribute to particle acceleration? The simulations targeted in this project will also allow particle movement to be traced to produce a physically-clear understanding of how modification of the shock affects the particle acceleration process.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.

该项目将开发一个新的计算框架，用于建模高能量颗粒的天体物理来源。在太空中，绝大多数可见物质由热电汽油（称为血浆）组成。 等离子体的天体物理流动可以非常快地移动，变得湍流并产生冲击波。 这种等离子体湍流是广泛的空间和天体物理问题的关键，包括黑孔积聚磁盘，超新星爆炸，恒星形成甚至太空天气。 湍流等离子体中的某些颗粒通过与湍流运动和冲击波相互作用，从而获得了巨大的能量。在不同的设置中，这些颗粒可以称为宇宙射线，太阳能颗粒或拾取离子。 尽管这些颗粒获得能量，但它们也会改变冲击波的结构，以及湍流的基本特征。 在该项目中，将通过扩展一个已成功用于模拟汽车发动机湍流燃烧的粒子相互作用的理论框架来开发这种相互作用的新理论模型。 将制作最先进的模拟，以检查能量颗粒如何改变等离子体的湍流和冲击。 这些模拟将对能量颗粒如何通过天体物理等离子体移动，并可能对改善空间天气预测产生实际影响，以帮助最大程度地减少卫星辐射损伤。 该项目还将支持提高高性能计算中学生和专业人员之间多样性的努力。铂湍流和不稳定性在将颗粒加速到高能量方面起着基本作用。随着颗粒获得能量，它们与周围的等离子体相互作用，与某些类型的血浆波共鸣，以稳定它们，同时破坏他人的稳定，并以尚未完全量化或理解的方式改变背景湍流的特征。 与湍流背景等离子体的这种相互作用是加速多种能量颗粒（包括高能宇宙射线，太阳能颗粒和拾音离子）的关键。 在该项目中，将通过扩展用于多组分的湍流工程流和燃烧的最新模型来生成一种新的计算模型和用于模拟多种压缩等离子体湍流的工具。 该模型将自愿包括等离子体上的能量粒子反馈。 该项目的主要重点是在通过能量颗粒修饰时对冲击结构和周围的湍流产生高质量的模拟。 这将解决几个开放问题：（1）能量颗粒如何改变冲击周围的湍流？ （2）能量颗粒如何改变冲击周围的磁场和磁性不稳定性？ （3）对冲击，湍流和磁性不稳定性的修改如何有助于颗粒加速？ 该项目中针对的模拟还可以追溯到粒子运动，以产生对冲击如何影响粒子加速过程的物理清晰的理解。该奖项反映了NSF的法定任务，并被认为是值得通过基金会的智力优点和更广泛影响的审查标准通过评估来获得支持的。

项目成果

Lagrangian Statistics of Heat Transfer in Homogeneous Turbulence Driven by Boussinesq Convection

布辛涅斯克对流驱动的均匀湍流传热的拉格朗日统计

• DOI: 10.3390/fluids5030127
• 发表时间: 2020
• 期刊: Fluids
• 影响因子: 1.9
• 作者: Pratt, Jane;Busse, Angela;Müller, Wolf-Christian
• 通讯作者: Müller, Wolf-Christian

Lagrangian Statistics for Dispersion in Magnetohydrodynamic Turbulence

磁流体动力湍流中色散的拉格朗日统计

• DOI: 10.1029/2020ja028245
• 发表时间: 2020
• 期刊: Journal of Geophysical Research: Space Physics
• 作者: Pratt, J.;Busse, A.;Müller, W.‐C.
• 通讯作者: Müller, W.‐C.

Intermittency of many-particle dispersion in anisotropic magnetohydrodynamic turbulence

各向异性磁流体动力湍流中多粒子分散的间歇性

• DOI: 10.1088/1742-6596/1620/1/012015
• 发表时间: 2020
• 期刊: Journal of Physics: Conference Series
• 作者: Pratt, J.;Busse, A.;Müller, W.-C.
• 通讯作者: Müller, W.-C.

Reynolds number dependence of Lagrangian dispersion in direct numerical simulations of anisotropic magnetohydrodynamic turbulence

各向异性磁流体动力湍流直接数值模拟中拉格朗日色散的雷诺数依赖性

• DOI: 10.1017/jfm.2022.434
• 发表时间: 2022
• 期刊: Journal of Fluid Mechanics
• 影响因子: 3.7
• 作者: Pratt, J.;Busse, A.;Müller, W.-C.
• 通讯作者: Müller, W.-C.