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On Vortical Structures in Near-Wake Region of a Cubic Obstacle Mounted on a Channel Wall
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 Title & Authors
On Vortical Structures in Near-Wake Region of a Cubic Obstacle Mounted on a Channel Wall
Hwang, Jong-Yeon; Yang, Gyeong-Su;
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Vortical structures in the near-wake region of a cubic obstacle are studied using numerical simulation. We consider flow between two parallel plates with a cube mounted on one of the plates. In the turbulent near-wake region of the flow, coherent structures such as hairpin vortices are found. Quasi-periodic behavior of the hairpin vortices is noticed; its dimensionless frequency at Re=1,000 is about 0.82 which is consistent with the result of Elavarasan of et al.'s experiment [Fluid Dyn. Research, 2000, 27] although their geometry is somewhat different from on. In the case of Re=3,500, the dimensionless frequency of the hairpin vortex is about 1.60. It is observed that the translating speed of the head of the hairpin vortex is lower than the streamwise mean velocity at that location. In the vicinity of the lower plate downstream of the cube, various length scales are identified thus less coherent. However, it is noticed that the vortical structures become gradually elongated downstream of the new reattachment.
Horseshoe Vortex;DNS;Hairpin Vortex;Coherent Structure;
 Cited by
장애물 주위의 와구조 형성과정에 관한 수치적 연구,황종연;양경수;

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