沟槽壁湍流减阻机理的氢气泡流动显示及数字图像分析  

Hydrogen Bubble Flow Visualization and Digital Image Analysis for Drag Reduction Mechanism in Wall Turbulence with Groove-Riblet Surface

作　　者：常跃峰[1,2] 姜楠[1,3] 夏振炎[1,3] 田砚[1,3] 

机构地区：[1]天津大学机械工程学院,天津300072 [2]山东工商学院管理科学与工程学院,烟台264005 [3]天津市现代工程力学重点实验室,天津300072

出　　处：《天津大学学报》2009年第9期839-844,共6页Journal of Tianjin University(Science and Technology)

基　　金：国家自然科学基金重点资助项目(10832001);国家自然科学基金资助项目(10872145);教育部高等学校新世纪优秀人才支持计划;天津市科技发展计划(06TXTJJC13800);上海市应用数学与力学研究所对外开放课题

摘　　要：应用氢气泡流动显示和数字图像处理技术,对微型沟槽壁面平板湍流边界层的减阻机理进行了实验研究.对开口循环水槽中沟槽壁面及光滑平板壁面湍流边界层近壁区高低速条带流动结构及其猝发现象进行了氢气泡流动显示,应用"帧间比较"定量分析方法,获得了水平平面内流向脉动速度、展向脉动速度的平面分布,并对沟槽壁面和平板壁面近壁面区域湍流相干结构的氢气泡流动显示图像进行了比较分析,根据流向脉动速度、展向脉动速度的平面分布分析了沟槽壁面及光滑平板壁面湍流边界层近壁区高低速条带结构的展向尺度特征,从壁湍流相干结构控制的角度研究了沟槽壁面平板湍流边界层的减阻机理.The experimental investigation of drag reduction mechanism over micro-riblets surface in a turbulent boundary layer was carried out with hydrogen bubble flow visualization and digital image processing techniques. The burst phenomena of high-speed and low-speed streak flow structures in the near wall region of turbulent boundary layer was visualized over both smooth plate and riblet plate in an open-surface recirculating water channel. With ＇comparison-between-frame＇ quantitative analysis technique,the two-dimensional plane distributions of longitudinal and lateral velocity components were obtained through processing and analyzing hydrogen bubble flow visualization images. Comparative analysis of the hydrogen bubble flow visualization images of coherent structures in the near wall region over smooth plate and riblet plate was conducted. The spatial scale characteristics along longitudinal and lateral directions of high-speed and low-speed streak flow structures in the near wall region of turbulent boundary layer were studied over both smooth plate and riblet plate surface according to the two-dimensional plane distributions of longitudinal and lateral velocity components. The mechanism of drag reduction over micro-riblets surface in a turbulent boundary layer was analyzed according to coherent structure manipulation in wall turbulence.

关 键 词：壁湍流 沟槽壁面 减阻 相干结构 流动控制 流动显示 

分 类 号：O357[理学—流体力学]