G1104 Vortex Wake from a Non-Parallel Pair of Circular Cylinders in a Uniform Flow

2001 ◽  
Vol 2001 (0) ◽  
pp. 250
Author(s):  
Riho Hiramoto ◽  
Hiroshi Higuchi
Keyword(s):  
Uniform Flow ◽  
Circular Cylinders ◽  
Vortex Wake ◽  
Parallel Pair

scholarly journals Vortex Wake from Tapered and Stepped Circular Cylinders in a Uniform Flow.

1993 ◽  
Vol 59 (559) ◽  
pp. 684-690 ◽  
Author(s):  
Junichiro Fukutomi ◽  
Yoshiyuki Nakase ◽  
Misao Takikawa
Keyword(s):  
Uniform Flow ◽  
Circular Cylinders ◽  
Vortex Wake

Effect of a Vibrating Upstream Cylinder on a Stationary Downstream Cylinder

1986 ◽  
Vol 108 (2) ◽  
pp. 180-184 ◽  
Author(s):  
M. Moriya ◽  
H. Sakamoto
Keyword(s):  
Reynolds Number ◽  
Transverse Vibration ◽  
Flow Patterns ◽  
Uniform Flow ◽  
Circular Cylinders ◽  
Tandem Arrangement ◽  
Cylinder Diameter ◽  
Spacing Ratio ◽  
Lock In

The flow around two circular cylinders in tandem arrangement in uniform flow where the upstream cylinder is forcibly vibrated in direction normal to the approach flow was experimentally studied at Reynolds number of 6.54 × 104. The spacing ratio 1/d (1: distance between centers of cylinders, d: diameter of circular cylinders) and the ratio of amplitude to cylinder diameter a/d (a: amplitude of transverse vibration of cylinder) were varied from 2 to 6 and 0 to 0.029 respectively. The effects of the vibration of the upstream cylinder on the downstream cylinder were discussed. In particular, two distinct “lock-in” regions were observed when the upstream cylinder was vibrated with a spacing ratio of 1/d = 3.0. The cylinder vibration was so effective even for a/d as small as 0.017 to cause two different flow patterns.

Stability of a circular cylinder oscillating in uniform flow or in a wake

1973 ◽  
Vol 61 (4) ◽  
pp. 769-784 ◽  
Author(s):  
Y. Tanida ◽  
A. Okajima ◽  
Y. Watanabe
Keyword(s):  
Circular Cylinder ◽  
Vortex Formation ◽  
Longitudinal Mode ◽  
Longitudinal Direction ◽  
Transverse Mode ◽  
Reynolds Numbers ◽  
Uniform Flow ◽  
Transverse Oscillation ◽  
Circular Cylinders ◽  
Drag Forces

The lift and drag forces were measured on both a single circular cylinder and tandem circular cylinders in uniform flow at Reynolds numbers from 40 to 104, to investigate the stability of an oscillating cylinder. A cylinder (the downstream one in the tandem case) was made to oscillate in either the transverse or longitudinal direction (perpendicular or parallel to the stream). In the case of a single cylinder, its oscillation causes the so-called synchronization in a frequency range around the Strouhal frequency (transverse mode) or double the Strouhal frequency (longitudinal mode). The aerodynamic damping for transverse oscillation becomes negative in the synchronization range. In the case of tandem cylinders, at low Reynolds numbers in the pure Kármán range synchronization was observed to occur only when the downstream cylinder oscillated inside the vortex-formation region of the upstream one, and at high (low subcritical) Reynolds numbers synchronization occurred irrespective of the cylinder spacing in either oscillating mode. In the tandem case, too, the transverse oscillation of the downstream cylinder becomes unstable in the range of synchronization.

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