摘要
采用时变粒子图像速度场测试技术(TR-PIV),对低速循环水槽中贴壁二维方柱绕流湍流场进行了细致的测量。通过对实验得到的30000个连续瞬态速度场进行分析,得到了时均速度场和流线图谱,以及流向、法向速度分量的脉动强度场和涡量场。此外,对脉动速度时序信号进行谱分析,得到了流场中低频大尺度相干结构脱落频率。通过对瞬态速度场的分析,揭示了贴壁方柱绕流的旋涡脱落及其发展过程。
The turbulent flow past a two-dimensional square cylinder flush-mounted on a plane wall was extensively measured by time-resolved particle image velocimetry （TR-PIV）.Toward this end, a low-speed recirculation water channel was established. Characteristics of the flow were statistically analyzed on 30,000 consecutive velocity maps in terms of time-averaged streamline pattern, velocity field, turbulence intensity and vorticity distributions. Existence of low - frequency coherent vortical structure embedded in the turbulent flow was revealed in terms of spectral analysis. The vortex shedding and development processes were described using the instantaneous velocity fields.
出处
《实验流体力学》
EI
CAS
CSCD
北大核心
2009年第2期31-35,共5页
Journal of Experiments in Fluid Mechanics
基金
国家自然科学基金(50606024)
NSFC-KOSEF基金(50711140398)资助项目
关键词
方柱
TR—PIV
分离流
再附湍流
相干结构
相关分析
square cylinder
TR-PIV
separated flow
reattaching turbulent flow
coherent structure
correlation analysis
