Formulating a theoretical scaling for dispersion in MHD turbulence

制定 MHD 湍流中色散的理论标度

• 批准号: 2212958
• 负责人: Jane Pratt
• 金额: $ 30.52万
• 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: 2022
• 资助国家: 美国
• 起止时间: 2022-06-15 至 2025-05-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2212958&HistoricalAwards=false
• 关键词: Formulating; theoretical; scaling; dispersion; MHD

One of the most fundamental aspects of turbulent flows is dispersion – a measure of how particles spread out. In electrically neutral fluids such as air and water, dispersion determines how moisture, particulates, or chemicals mix into the atmosphere or oceans. Other fluids, like liquid metals and plasmas, can carry an electrical charge. Their movement is fundamentally changed by the presence of magnetic fields and is described by magnetohydrodynamics. Dispersion in magnetohydrodynamic fluids determines the properties of space weather as plasma spreads in the interstellar medium, how chemicals from the core of a star are mixed into its outer layers, and how particles are trapped in the liquid metal blankets of reactors. The goal of this project is to provide a clear understanding of how magnetohydrodynamic dispersion differs from dispersion in the hydrodynamic case observed in air or water. This project will include summer research students, a computational physics outreach program using scientific visualizations and computer renderings, and technical training for the scientific/industrial work force.This project will leverage modern ideas and theoretical techniques to modify and extend the theory of dispersion, developed by Richardson in 1926 for hydrodynamic fluids, to the setting of magnetohydrodynamic fluids. Testing our new prediction will require simulations that are particularly intensive; these simulations will be performed on some of the largest supercomputers in the world. The simulation data will allow our theoretical results to probe questions of foundational importance for magnetohydrodynamic turbulence. These include how a turbulent flow develops a preferred direction of movement, and how different parts of the flow interact energetically. The results of our theoretical and computational investigation will allow engineers to design more efficient reactors, and astronomers to better predict the space weather that impacts life on Earth.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.

湍流最基本的方面之一是分散 - 衡量颗粒的分布方式。在空气和水等电中性液体中，分散确定水分，成分或化学物质如何混合到大气或海洋中。其他流体，例如液体金属和等离子体，可以携带电荷。它们的运动从根本上通过磁场的存在改变，并用磁流体动力学描述。随着血浆在星际介质中扩散，恒星核心的化学物质如何将其混合到其外层中，以及如何将颗粒捕获在反应堆的液态金属毯中，磁性水力动力流体的分散确定了太空天气的特性。该项目的目的是清楚地了解磁流体动力分散与在空气或水中观察到的流体动力学病例中的分散剂的不同。该项目将包括夏季研究专业的学生，​​使用科学可视化和计算机效果图的计算物理外展计划，以及对科学/工业劳动力的技术培训。该项目将利用现代思想和理论技术来修改和扩展1926年理查德（Richardson）在1926年开发的和扩展磁性流体的磁性流体，以进行磁性流体动力。测试我们的新预测将需要特别密集的模拟；这些模拟将对世界上一些最大的超级计算机进行。模拟数据将使我们的理论结果探究对磁流体动力湍流的基础重要性问题。其中包括湍流如何发展出首选的运动方向，以及流动的不同部分如何有效相互作用。我们的理论和计算调查结果将使工程师能够设计更有效的反应堆，而天文学家可以更好地预测影响地球生命的太空天气。该奖项反映了NSF的法定任务，并通过使用基金会的知识分子优点和更广泛的影响标准来评估通过评估来诚实地对其进行评估。