Research on vortexes of cross flow past a horizontal circular cylinder by PIV system
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摘要: 应用粒子图像测速(PIV)系统对横流中近壁水平圆柱绕流进行了试验研究。介绍了试验原理及装置,讨论了试验参数的选取和粒子的跟随性问题。分析了上游来流的流动特性,显示了亚临界雷诺数下间隙比为0.5时圆柱后尾流区旋涡产生、发展和消亡的动态过程,比较了时均流场和瞬时流场旋涡结构。对圆柱尾迹的旋涡脱落特性进行了分析,得出在试验条件下斯特劳哈尔数保持为常数0.2的结论。Abstract: The experimental research on cross flow pasting a circular cylinder near a plane boundary is conducted based on the particle image velocimetry(PIV)system. The experimental principle and devices are introduced. The problems about parameter's selection and particle's tracking are discussed. And the flow characteristics of the upstream of the cylinder are analyzed. Behind the cylinder,the dynamic process of the vortex formation,its development and extinction are displayed on the sub-critical Reynolds number range and gap-ratio is 0.5. The structure of the time-average and instantaneous flow field is compared. Finally,the characteristics of the vortex shedding in the wake are analyzed. Under the given experimental condition,the conclusion is drawn that the Strouhal number keeps the constant of 0.2.
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Keywords:
- particle image velocimetry /
- cross flow /
- flow past circular cylinder /
- vortex /
- Strouhal number /
- Reynolds number
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