Turbulent transport in anisotropic velocity fields

智力价值：提出的研究的总体目标是探索在各向异性湍流情况下湍流传热的基本机制。项目期间的具体目标是：(a)研究靠近固体边界的湍流输送的物理机制（在粘性壁面区域和对数层）；(b)确定普朗特数对湍流输运性质的影响（例如湍流普朗特数和努塞尔数）；(c)开发模拟热和流体耦合流动和化学反应湍流的算法。提出的方法是利用直接数值模拟产生的流体力学来生成湍流色散的拉格朗日数据。这种拉格朗日方法允许研究具有实际意义但性质不同的流体（例如，液态金属、气体、制冷剂、电化学流体），并研究常规数值方法在超级计算机当前能力下往往不可行的情况。提议活动的更广泛影响：这项研究的发现将对湍流输运理论以及工业和环境应用具有重要意义，其中湍流输运建模是重要的（例如，化学反应器的设计，不同普朗特数流体的热交换器的设计，污染物扩散的预测和控制，移动叶片的传热）。拟议研究项目的各个方面将有助于继续教育课程的发展。此外，通过该项目生成的数据库将通过我们小组已经在运行的web服务器提供给社区。最后，将开始努力组织讲习班，重点是确定湍流运输中的建模问题和可作为验证基准的数据库。

Intellectual Merit: The overall goal of the proposed research is to explore the fundamental mechanism of turbulent heat transfer in the case of anisotropic turbulence. The specific objectives for the duration of the project are to: (a) investigate the physical mechanisms for turbulent transport close to a solid boundary (in the viscous wall region and in the logarithmic layer); (b) determine the Prandtl number effects on turbulent transport properties (e.g., on the turbulent Prandtl number and on the Nusselt number); (c) develop algorithms for the simulation of coupled heat and fluid flow and for chemically reacting turbulent flows. The proposed approach is to use hydrodynamics generated by direct numerical simulations to generate Lagrangian data for turbulent dispersion. This Lagrangian approach allows to investigate fluids of practical interest but different properties (e.g., liquid metals, gases, refrigerants, electrochemical fluids), and to investigate cases where conventional numerical methods are often not feasible with the current capabilities of supercomputers.Broader Impact of the Proposed Activities: The findings of this research will be significant for the theory of turbulent transport as well as for industrial and environmental applications, in which modeling turbulent transport is important (e.g., design of chemical reactors, design of heat exchangers for different Prandtl number fluids, prediction and control of pollutant dispersion, heat transfer over moving blades).Aspects of the proposed research project will be instrumental in the development of a continuing education course. In addition, the database generated through this project will become available to the community through a web server that our group is already operating. Finally, an effort will be initiated to organize workshops focused on the identification of modeling issues in turbulent transport and of databases that can serve as validation benchmarks.