CDS&E: Studying Multiscale Fluid Turbulence via Open Numerical Laboratories

1507469(梅内沃)这个项目的目标是通过产生新的高保真数据并将这些新数据提供给全国科学界，来发现湍流中的新基本现象。将探索湍流的基本特征，这些特征取决于在湍流中观察到的多个时间和长度尺度，并将开发能够进行这种分析的软件工具，并向研究界提供。拉格朗日混沌和向湍流的转变将使用大量计算机模拟产生的数据集进行研究，这些数据集被吸收到网络可访问的开放数值实验室中。众所周知，向湍流的转变是通过一系列具有高度时空复杂性的现象来实现的。然而，关于拉格朗日混沌如何在多个尺度的湍流中表现出来，以及如何更好地描述湍流的过渡行为，人们知之甚少。众所周知，湍流还包含最小尺度的涡旋结构和大尺度的涡旋结构。该项目旨在回答有关多尺度涡旋结构的分级组织及其与能量级联的关系的基本问题。联合PIS开发了一个开放的、基于计算数据的湍流实验室，在那里，更广泛的研究社区可以获得整个时空数据。该项目将进一步开发4D流量数据集的多尺度版本，有效地为数据增加第五维(尺度)。虽然约翰·霍普金斯大学目前可用的资源主要集中在各向同性湍流上，但拟议中的工作将把数据扩展到比各向同性湍流更复杂的其他情况，如沟道流动数据。数据的可获得性和分析工具的可获得性将使湍流研究发生阶段性变化，可能通过普及对高质量模拟数据的访问来改变研究人员在这一领域的工作方式。主要基于MatLab的教育模块还将允许学生以前所未有的详细程度查询模拟数据集。

1507469(Meneveau)The goal of this project is to discover new fundamental phenomena in turbulent flow by generating new high fidelity data and by making these new data available to the whole scientific community of the Nation. Basic features of turbulence that depend on the multiple time and length scales observed in turbulent flows will be explored, and software tools that enable such analysis will be developed and offered to the research community. Lagrangian chaos and transition to turbulence will be studied using datasets arising from massive computer simulations that are ingested into web-accessible, open numerical laboratories. It is known that the transition to turbulence occurs through a sequence of phenomena characterized by high spatio-temporal complexity. However, very little is known about how Lagrangian chaos manifests itself at the multiple scales of turbulence, and how transitional behavior of turbulence may be better characterized. Turbulence also is known to contain vortical structures at the smallest scales, and at large-scales. This project aims to answer fundamental questions about the hierarchical organization of vortical structures at multiple scales and their relationship to the energy cascade. The co-PIs have developed an open, computational data-enabled turbulence laboratory where the entire space-time data is available to the wider research community. The project will further develop multiscale versions of the 4D flow datasets, effectively adding a 5th dimension (scale) to the data. While the currently available resource at Johns Hopkins is focused on isotropic turbulence, the proposed effort will extend the data to other more complex cases than isotropic turbulence, like channel flow data. Availability of data and availability of analysis tools will enable a step change in turbulence research, possibly transforming the way researchers work in this area by democratizing access to high-quality simulation data. Educational modules, mostly based on Matlab, will also allow students to query simulation datasets in unprecedented detail.