Dissipation and Kinetic Physics of Astrophysical Turbulence

湍流是与流体、气体和等离子体相关的基本物理现象之一。 在天体物理现象中，湍流提供了一种有效的能量、动量和粒子输运机制，因此在天体物理物体的动力学中起着关键作用。由于可以从航天器获得测量数据，太阳风已成为研究湍流的独特实验室。 因此，人们已经做出了相当大的努力来研究太阳风湍流使用的观测，理论和计算工具相结合。虽然对这一现象的基本物理学的理解已经取得了很大进展，但仍有大量关键问题没有得到解答。该项目建议使用Blue沃茨领导级计算系统来执行突破性的大规模模拟，以研究能量如何级联并最终在太阳风中消散。这项研究将显着推进湍流的知识状态，并将代表一个非常重要的里程碑，在努力进行现实的模拟太阳风湍流。此外，该项目的结果将极大的兴趣，以广大社区的研究人员对太阳风等离子体，日冕等离子体和等离子体天体物理学的工作。总的来说，这个项目是一个更大的基础科学研究流的一部分，这是中央的使命的NSF.一个特别具有挑战性的问题，这是这个建议的重点，是发生了什么事的能量级联到动力学尺度的磁流体动力学（MHD）湍流。这个问题不仅是基本的等离子体物理学的兴趣，但也直接关系到太阳风和太阳日冕加热的非常重要的问题，这是至关重要的理解太阳-地球相互作用，但迄今为止一直逃避一个结论性的解决方案。 这项研究将克服现有方法的许多局限性，并将提供补充信息，涵盖其他技术无法达到的效果和参数制度。计划中的蓝色沃茨三维模拟将达到磁流体动力学尺度，同时保留动力学效应，并将提供一个研究界提出的许多关键问题的一瞥。 此外，模拟将能够与航天器观测进行详细比较，并探索模拟中同时存在的竞争过程的作用。这些模拟中的丰富信息类似于从许多航天器飞行任务中收集的数据，值得整个社区进行分析。因此，该项目产生的模拟数据将提供给社区进行分析。

Turbulence is one of the fundamental physical phenomena associated with fluids, gasses, and plasmas. In astrophysical phenomena, turbulence provides a mechanism of efficient energy, momentum, and particle transport thus playing a key role in the dynamics of astrophysical objects. The solar wind has served as a unique laboratory for studies of turbulence due to the availability of measurements from spacecraft. Accordingly, considerable effort has been made to study solar wind turbulence using a combination of observational, theoretical, and computational tools. While understanding of the basic physics of this phenomenon has advanced greatly, a significant number of key questions remain unanswered. This project proposes to use the Blue Waters leadership class computing system to execute ground-breaking large scale simulations to investigate how energy cascades and is ultimately dissipated in the solar wind. This study will significantly advance the state of knowledge of turbulence and will represent a very important milestone in the efforts to perform realistic modeling of solar wind turbulence. Additionally, the project results will be of great interest to a wide community of researchers working on solar wind plasma, coronal plasma, and plasma astrophysics. Overall, this project is part of a larger stream of fundamental scientific research, which is central to the mission of the NSF.One particularly challenging question, which is the focus of this proposal, is what happens to the energy that is cascaded to kinetic scales by magnetohydrodynamic (MHD) turbulence. This question is not only of basic plasma physics interest, but is also directly related to the very important problem of solar wind and solar corona heating that is crucial to understanding of the Sun-Earth interaction, but has so far eluded a conclusive solution. This study will overcome many of the limitations of existing approaches and will provide complementary information covering effects and parameter regimes inaccessible to other techniques. The planned 3D simulations on Blue Waters will reach into the MHD scales while retaining kinetic effects and will provide a glimpse into many of the crucial questions posed by the research community. Additionally, the simulations will enable detailed comparison with spacecraft observations and exploration of the role of competing processes that are simultaneously present in the simulations. The wealth of information in these simulations is akin to data collected from many spacecraft missions and warrants analysis from the community at large. As such, the simulation data resulting from the project will be made available to the community for analysis.