Beyond incompressible phenomenology: mixing in compressible turbulent flows

PI: Donzis， diego提案号：1605914湍流中物质或物种（在文献中通常称为“标量”）的混合从基础和实践的角度来看都是一个至关重要的主题。本建议的重点是研究可压缩湍流和混合。为了实现这一目标，建议使用前所未有的高保真度的模拟，推动被称为直接数值模拟（DNS）的模拟类的边界。虽然在不可压缩流中混合的大量工作已经积累了几十年，但在可压缩湍流中混合的探索或数据没有类似的水平，尽管它在不同的领域至关重要，如航空运输和空气动力学，太阳风的物理学，恒星和超新星的流动，发动机或大气中的化学反应流动，等等。在实际应用中，通常使用主要基于经典现象学的不可压缩结果来模拟可压缩混合。因此，本提案旨在通过在新的规范配置中进行控制和系统的研究，为理解基本物理过程提供基础，并为社区探索高保真DNS数据数据库提供基础，从而弥补知识缺口。本研究将全面考察雷诺数、马赫数和施密特数的影响。提出的工作包括一类典型流的定义，可用于获得高保真度的结果，这可能导致可压缩标量混合的进展。这些规范流的结果将提供可靠的数据，可以用作理论和模型的基准。此外，提出了可压缩混合的所谓兰利曲线。作为该项目的副产品，高性能计算技术的开发和数据将提供给感兴趣的科学家和工程师社区。

PI: Donzis, DiegoProposal Number: 1605914Mixing of substances or species (commonly called "scalars" in the literature) in turbulent flows is a topic of paramount importance from both fundamental and practical standpoints. The focus of this proposal is on the investigation of compressible turbulent flows and mixing. In order to achieve this goal, it is proposed to use simulations of unprecedented high fidelity, pushing the boundaries of the class of simulations known as Direct Numerical Simulations (DNS). While substantial work has been accumulated over decades on mixing in incompressible flows, there is no similar level of exploration or data on mixing in compressible turbulence in spite of its critical importance in diverse areas such as air transportation and aerodynamics, physics of solar wind, flows in stars and supernovae, chemically reacting flows in engines or the atmosphere, among many others. In applications, compressible mixing is commonly modeled using incompressible results based mainly on classical phenomenology. There is, thus, a gap in knowledge which this proposal aims to close by providing groundwork for understanding the fundamental physical processes through controlled and systematic studies in new canonical configurations and the resulting databases of high-fidelity DNS data for the community to explore. The proposed research will comprehensively investigate the effects of Reynolds number, Mach number and Schmidt number. The work proposed includes the definition of a class of canonical flows that can be used to obtain high fidelity results that could lead to advances in compressible scalar mixing. Results for these canonical flows would provide reliable data that can be used as benchmark for theories and models. Furthermore, it is proposed to develop a so-called Langley curve for compressible mixing. The high performance computing techniques to be developed as the side effect of this project and the data will be available to the community of interested scientists and engineers.