A PENULTIMATE PETASCALE COMPUTATIONAL LABORATORY FOR TURBULENCE AND MAGNETOHYDRODYNAMIC TURBULENCE

该项目的目标是利用Blue沃茨超级计算机，为高雷诺数湍流的尺度相似性研究以及受外部磁场和固体旋转影响的湍流行为的研究做出持久的贡献。先进的后处理技术和飞行中处理技术将被应用于从迄今为止最大的湍流模拟（超过50万亿格点）中提取独特的物理见解，旨在通过priorPRAC分配实现精细尺度结构。仔细选择的参数和初始条件将允许第一个数值模拟的响应的湍流与经典的惯性范围内的电磁感应力，以及均匀的固体旋转。 该项目预计将对许多研究领域产生重大影响，如气象学，燃烧，风力发电，必须考虑强湍流的间歇性爆发。此外，研究磁场和固体旋转对湍流的综合影响将为我们理解地球磁场是如何产生的提供关键步骤。此外，通过提供该项目产生的新数据，对基础湍流研究的影响可能是变革性的。长期以来，对适用于不同几何形状的高雷诺数湍流的精细尺度相似性问题的结论性结果的搜索一直是湍流理论的一个巨大挑战。拟议研究的智力价值部分在于对高分辨率模拟数据的严格分析，这些数据最终显示出在这一追求中实现倒数第二个描述的希望。与旋涡结构有关的极端事件的时间分辨动力学信息将特别是新的，特别是在蓝沃茨可能的高雷诺数下。对于磁流体动力学（MHD）湍流，新的模拟预计将满足理解流动物理的挑战，同时满足更高的雷诺数，域的大小，特别是沿着施加磁场的方向，和不同的时间尺度与后者的强度相关联的竞争需求。考虑耦合MHD湍流与固体旋转也提出了许多进一步的复杂性，提出的模拟将提供一个基本的表征以前没有在文献中。最后，持续访问蓝色沃茨将为该项目的博士生提供成为下一代计算科学家领导者的机会。

The objective of this project is to use the Blue Waters supercomputer to enable lasting contributions to the study of scale similarity in turbulent flows at high Reynolds number, and of the behavior of turbulent flows subjected to an external magnetic field and solid-body rotation. Advanced post and on-the-fly processing techniques are to be applied to extract unique physical insights from the largest turbulence simulation to date (over half a trillion grid pints) aimed at fine-scale structure, made possible through a priorPRAC allocation. A careful choice of parameters and initial conditions will allow the first numerical simulation of the response of turbulence with a classical inertial range to the forces of electromagnetic induction as well as uniform solid-body rotation. The project is expected to be of great impact for many fields of research such as meteorology, combustion, wind power, where intermittent outbursts of strong turbulence must be considered. Additionally, studying the combined effects of magnetic fields and solid-body rotation on a turbulent flow will provide crucial steps for our understanding how the Earth's magnetic field arises. Furthermore, by providing new data generated from this project, the impact on fundamental turbulence research is likely to be transformative.The search for conclusive results on the problem of refined scale similarity applicable to high Reynolds number turbulent flows in diverse geometries has long been a grand challenge in turbulence theory. The intellectual merit of the proposed research lies in part in the rigorous analysis of high-resolution simulation data that has finally shown promise of enabling a penultimate description in this pursuit. Time-resolved dynamical information on extreme events in connection to vortical structures will in particular be new especially at the high Reynolds number possible on Blue Waters. For magnetohydrodynamic (MHD) turbulence the new simulations are expected to meet the challenge of understanding the flow physics while meeting competing demands for higher Reynolds number, domain size especially along the direction of an imposed magnetic field, and different time scales associated with the strength of the latter. Consideration of the coupling MHD turbulence with solid-body rotation also raises many further complexities, for which the proposed simulations will provide a basic characterization previously not available in the literature. Finally, sustained access to Blue Waters will provide doctoral students in this project with opportunities towards becoming leaders in the next generation of computational scientists.