US-UK Cooperative Research: Structure of Turbulence Near Density Interfaces

美英合作研究：近密度界面湍流结构

• 批准号: 8922496
• 负责人: Harindra Joseph Fernando
• 金额: $ 1.45万
• 依托单位: Arizona State University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 1990
• 资助国家: 美国
• 起止时间: 1990-07-15 至 1994-06-30
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=8922496&HistoricalAwards=false
• 关键词: US; UK; Cooperative; Research; Structure

This award will support collaborative research in mechanical engineering between Dr. Harindra Fernando, Arizona State University and Dr. J.C.R. Hunt, Department of Applied Mathematics and Theoretical Physics, University of Cambridge, England. The objective of the proposed research is an investigation of the structure of turbulence near density interfaces. The research will be mainly of a theoretical/numerical nature (to be carried out at the University of Cambridge), but complementary laboratory experiments (to be performed at Arizona State University) are also proposed. The development of a clear understanding of the physical processes associated with turbulent mixing across density interfaces and the modelling of such phenomena continue to be challenging problems in fluid mechanics. The proposed research will be based on a new technique, the so-called "kinematic simulation of turbulence", which has been developed by Dr. Hunt's group at Cambridge. This particular approach differs from earlier ones in the sense that the effects of "small" turbulent eddies, advected over the interface by randomly moving "large" eddies of different sizes and frequencies, are explicitly considered. The internal-wave generation at the interface is directly related to this advection. The analysis will be performed for several flow configurations of geophysical and engineering interest, that include density interfaces subjected to velocity shear and zero-mean-shear turbulence. The theoretical predictions will be compared with the laboratory measurements. The results of this study will contribute substantially to the understanding of turbulent mixing across density interfaces. The project will benefit from the extensive and complementary expertise of the two investigators on the topic of turbulence in homogenous, stratified and rotating flows.

该奖项将支持机械领域的合作研究 亚利桑那州立大学的Harindra Fernando博士 还有J.C.R.博士亨特，应用数学系和 英国剑桥大学理论物理系。 的 拟议研究的目的是调查 密度界面附近的湍流结构。 这项研究将 主要是理论/数字性质（将在 剑桥大学），但补充实验室 实验（将在亚利桑那州立大学进行）是 并提出了 发展对物理过程的清晰理解 与穿过密度界面的湍流混合有关， 对这种现象进行建模仍然是一个具有挑战性的问题 在流体力学中。拟议的研究将基于新的 技术，即所谓的“湍流运动学模拟”， 这是由剑桥的Hunt博士的团队开发的。 这 一种特殊的方法不同于早期的方法， “小”湍流涡旋的影响，平流在 通过随机移动不同大小的“大”涡流， 频率，是明确考虑的。 内波 界面处的生成与该平流直接相关。 将对以下几种流动配置进行分析： 地球物理和工程方面的兴趣，包括密度 受到速度剪切和零平均剪切的界面 急流. 理论预测将与 实验室测量。 这项研究的结果将 对理解湍流混合有很大贡献 跨密度接口。该项目将受益于 两名调查员在以下方面具有广泛和互补的专门知识： 均匀、分层和旋转中的湍流问题 流动。