Proceedings of the KSME Conference (대한기계학회:학술대회논문집)
- 2000.11b
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- Pages.404-409
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- 2000
A Study on Characteristics of Secondary Vortices in the Near Wake of a Circular Cylinder by PIV Measurement
PIV 계측에 의한 실린더 근접후류에서 2차 와류의 특성 연구
- Published : 2000.11.02
Abstract
Characteristics of secondary vortices is topologically investigated in the near-wake region of a circular cylinder where the Taylor hypothesis does not hold. The three-dimensional flow fields in the wake-transition regime were measured by a time-resolved PIV. For the analysis in a moving frame of reference, the convection velocity of the Karman vortices is evaluated from the trajectory of vortex center which is defined as the centroid of the vorticity field. Then, a saddle point is obtained by applying the critical point theory. Science the distributions of fluctuating Reynolds stresses defined by triple-decomposition are closely related with the existence of secondary vortices. the physical meaning of them is explained in conjunction with vortex center and saddle point trajectories. Finally, the temporal evolution of streamwise vortex is also discussed.
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