Resolving the Structure of Turbulence in Rough Wall Channel Flows Using 3D, Time Resolved, Multiscale Velocity Measurements

使用 3D、时间分辨、多尺度速度测量来解析粗糙壁通道流中的湍流结构

• 批准号: 1438203
• 负责人: Joseph Katz
• 金额: $ 15.9万
• 依托单位: Johns Hopkins University
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-09-01 至 2017-08-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1438203&HistoricalAwards=false
• 关键词: Resolving; Structure; Turbulence; Rough; Wall

PI: Katz, JosephProposal Number: 1438203 The proposed research aims to explore how turbulence is generated and sustained close to solid boundaries. It will use findings from very accurate experiments to clarify the way that energy is transferred in turbulent flows between the different regions of the flow. As such, this research would allow the development of correct models for the design of flow systems where solid walls are present, which are in fact the most common cases of turbulent flows in industry and the environment. Educational activities involve graduate and undergraduate students for the development and implementation of the proposed measurement system. There are also activities planned for Baltimore City high-school students to work yearlong in the PI?s laboratory as part of their required Research Practicum.This work will investigate how the roughness height, wavelength, spatial arrangement and uniformity, affect the generation of vortices, their evolution in time, their interactions with vortices away from the wall, and impact of these interactions on turbulence statistics. A rather comprehensive and non-trivial experimental approach is proposed: A 3D time-resolved tomographic PIV will resolve small-scale turbulence near the wall, while digital holographic microscopy (DHM) will be used to simultaneously observe the large scale structures away from the wall. The combined TPIV-DHM instrument would resolve 3.5 orders of magnitude of length scales.

PI：Katz，JosephProposal Number：1438203拟议的研究旨在探索湍流是如何在固体边界附近产生和维持的。它将使用非常精确的实验结果来阐明能量在湍流中在不同区域之间传递的方式。因此，这项研究将允许开发正确的模型，用于设计存在固体壁的流动系统，这实际上是工业和环境中最常见的湍流情况。教育活动涉及研究生和本科生的发展和实施拟议的测量系统。也有活动计划为巴尔的摩市高中学生工作一年的PI？这项工作将调查粗糙度的高度，波长，空间布置和均匀性，如何影响涡流的产生，它们的演变，它们与远离壁的涡流的相互作用，以及这些相互作用对湍流统计的影响。提出了一种相当全面和非平凡的实验方法：三维时间分辨层析PIV将解决近壁的小尺度湍流，而数字全息显微镜（DHM）将被用来同时观察远离壁的大尺度结构。组合的TPIV-DHM仪器将分辨3.5个数量级的长度尺度。