Active control of asymmetric vortex effects in a circular cylinder

1986 ◽  
Vol 23 (2) ◽  
pp. 136-140
Author(s):  
Takashi Abe ◽  
Katushi Funabiki
Author(s):  
Haecheon Choi

In this paper, we present two successful results from active controls of flows over a circular cylinder and a sphere for drag reduction. The Reynolds number range considered for the flow over a circular cylinder is 40∼3900 based on the free-stream velocity and cylinder diameter, whereas for the flow over a sphere it is 105 based on the free-stream velocity and sphere diameter. The successful active control methods are a distributed (spatially periodic) forcing and a high-frequency (time periodic) forcing. With these control methods, the mean drag and lift fluctuations decrease and vortical structures are significantly modified. For example, the time-periodic forcing with a high frequency (larger than 20 times the vortex shedding frequency) produces 50% drag reduction for the flow over a sphere at Re = 105. The distributed forcing applied to the flow over a circular cylinder results in a significant drag reduction at all the Reynolds numbers investigated.


2021 ◽  
Vol 33 (10) ◽  
pp. 103604
Author(s):  
Yu-Fei Mei ◽  
Chun Zheng ◽  
Nadine Aubry ◽  
Meng-Ge Li ◽  
Wei-Tao Wu ◽  
...  

2013 ◽  
Vol 56 (5) ◽  
pp. 1186-1197 ◽  
Author(s):  
JianSheng Wang ◽  
YuanXin Xu ◽  
YongSheng Tian

2007 ◽  
Vol 78 (3-4) ◽  
pp. 383-407 ◽  
Author(s):  
A. Naim ◽  
D. Greenblatt ◽  
A. Seifert ◽  
I. Wygnanski

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