Long Time Scale Fluctuation in the Irregularity of Vortex Shedding. Spectral Analysis of the Local rms Value and Criculation.
Long Time Scale Fluctuation in the Irregularity of Vortex Shedding. Spectral Analysis of the Local rms Value and Criculation.
复制标题
涡旋脱落不规则性的长时间尺度波动。
DOI：
10.1299/kikaib.61.379
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发表时间：
1995
期刊：
影响因子：
--
通讯作者：
Y. Obata
中科院分区：
文献类型：
--
作者：
H. Haniu;H. Sakamoto;Jun Nakamura;Y. Obata
本文对圆柱体旋涡脱落的不规则性进行了实验研究。研究的基础上的频谱分析的局部均方根值的速度脉动后的圆柱。为了研究速度脉动与环量脉动之间的关系，对用PIV和氢泡从剪切层分离点附近延伸的条纹线图像处理得到的涡环量进行了谱分析。从这项研究中，长时间尺度的周期性波动，约20倍的旋涡脱落的周期性，澄清。此外，当地的均方根值的时间变化和环流的时间变化之间有很好的相关性。
Irregularity of vortex shedding from a circular cylinder is studied experimentally. The study is based on a spectral analysis of local rms value of velocity fluctuation behind the circular cylinder. Spectral analysis of circulation of vortices obtained by both PIV and image processing of the streak line visualized by hydrogen bubbles extending from the location near the separation point of shear layer is made in order to investigate the relationship between velocity fluctuations and circulation fluctuations. From this study, long time scale periodic fluctuation, approximately 20 times the vortex shedding periodicity, is clarified. Also a good correlation between the time variation of the local rms value and that of the circulation was obtained.