Flow-induced vibration on a circular cylinder in planar shear flow

2014 ◽  
Vol 105 ◽  
pp. 138-154 ◽  
Author(s):  
Jiahuang Tu ◽  
Dai Zhou ◽  
Yan Bao ◽  
Congqi Fang ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Circular Cylinder ◽  
Shear Flow ◽  
Flow Induced Vibration ◽  
Planar Shear

On a Circular Cylinder in a Uniform Planar Shear Flow at Subcritical Reynolds Number

2002 ◽  
Author(s):  
D. Sumner ◽  
O. O. Akosile
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Shear Flow ◽  
Lift Force ◽  
Experimental Studies ◽  
Reynolds Numbers ◽  
Low Velocity ◽  
Static Pressure Distribution ◽  
Planar Shear ◽  
The Mean

An experimental investigation was conducted of a circular cylinder immersed in a uniform planar shear flow, where the approach velocity varies across the diameter of the cylinder. The study was motivated by some apparent discrepancies between numerical and experimental studies of the flow, and the general lack of experimental data, particularly in the subcritical Reynolds number regime. Of interest was the direction and origin of the steady mean lift force experienced by the cylinder, which has been the subject of contradictory results in the literature, and for which measurements have rarely been reported. The circular cylinder was tested at Reynolds numbers from Re = 4.0×104 − 9.0×104, and the dimensionless shear parameter ranged from K = 0.02 − 0.07, which corresponded to a flow with low to moderate shear. The results showed that low to moderate shear has no appreciable influence on the Strouhal number, but has the effect of lowering the mean drag coefficient. The circular cylinder develops a small steady mean lift force directed towards the low-velocity side, which is attributed to an asymmetric mean static pressure distribution on its surface. The reduction in the mean drag force, however, cannot be attributed solely to this asymmetry.

An Experimental Study on Flow Induced Vibration of a Circular Cylinder in Shear Flow

2010 ◽  
Author(s):  
Ming Huei Yu ◽  
Yi-hsin Wu
Keyword(s):  
Circular Cylinder ◽  
Shear Flow ◽  
Test Section ◽  
Unit Length ◽  
Large Mass ◽  
Elastic Vibration ◽  
Mass Ratio ◽  
Flow Induced Vibration ◽  
Low Mass ◽  
Low Mass Ratio

The vibrations of a circular cylinder in both uniform and shear flows are investigated experimentally. For the experimental investigation, a low speed water tunnel was designed and built to provide either uniform or shear flow in the test section, depending on the upstream flow management. In the test section, a circular tube of various materials can be flexibly mounted for vibration testing. Two accelerators were carefully installed inside the tube so that one accelerator is sensitive to the cylinder vibration in the streamwise direction only, and the other in the cross-stream direction. The vibration amplitudes of the cylinder in the streamwise and cross-stream directions were simultaneously measured by the two accelerators, and recorded by a two-channel data acquisition system. The orbits of the cylinder motion can be drawn from the data. Experiments were conduced at various mass ratios (the ratio of the cylinder mass per unit length to its buoyancy force) and shear parameters (the non-dimensional velocity gradient of the approaching fluid flow to the cylinder). By analyzing the orbits and amplitude diagrams, it is found that both the shear parameter and mass ratio have profound effects on the cylinder vibration. The orbits of the cylinder in uniform flow are symmetric while they are asymmetric in shear flow. Vibration amplitude as a function of reduced velocity illustrates that the cylinder in uniform or shear flow does not vibrate at low reduced velocities but vibrate significantly beginning at the reduced velocity around 5, initiated by vortex-induced instability. At high reduced velocity, the circular cylinder in shear flow still vibrates at significant amplitude, an evidence of fluid elastic vibration. It is also shown by the amplitude diagrams that low mass ratio promotes the cylinder’s vibration while large mass ratio reduces the vibration.

End-wall effects on vortex shedding in planar shear flow over a circular cylinder

2011 ◽  
Vol 42 (1) ◽  
pp. 102-107 ◽  
Author(s):  
Zhiyong Huang ◽  
Helge I. Andersson ◽  
Weicheng Cui
Keyword(s):  
Circular Cylinder ◽  
Shear Flow ◽  
Vortex Shedding ◽  
Wall Effects ◽  
Planar Shear ◽  
End Wall

Dynamic responses and flow-induced vibration mechanism of three tandem circular cylinders in planar shear flow

2020 ◽  
Vol 199 ◽  
pp. 107022
Author(s):  
Jiahuang Tu ◽  
Xiaoling Tan ◽  
Xuhui Deng ◽  
Zhaolong Han ◽  
Min Zhang ◽  
...  
Keyword(s):  
Shear Flow ◽  
Dynamic Responses ◽  
Circular Cylinders ◽  
Flow Induced Vibration ◽  
Planar Shear ◽  
Vibration Mechanism

Vortex shedding from a circular cylinder in moderate-Reynolds-number shear flow

1980 ◽  
Vol 101 (4) ◽  
pp. 721-735 ◽  
Author(s):  
Masaru Kiya ◽  
Hisataka Tamura ◽  
Mikio Arie
Keyword(s):  
Reynolds Number ◽  
Circular Cylinder ◽  
Shear Flow ◽  
Vortex Shedding ◽  
Transverse Velocity ◽  
Number Range ◽  
Uniform Shear ◽  
Reynolds Number Range ◽  
Moderate Reynolds Number ◽  
Shear Parameter

The frequency of vortex shedding from a circular cylinder in a uniform shear flow and the flow patterns around it were experimentally investigated. The Reynolds number Re, which was defined in terms of the cylinder diameter and the approaching velocity at its centre, ranged from 35 to 1500. The shear parameter, which is the transverse velocity gradient of the shear flow non-dimensionalized by the above two quantities, was varied from 0 to 0·25. The critical Reynolds number beyond which vortex shedding from the cylinder occurred was found to be higher than that for a uniform stream and increased approximately linearly with increasing shear parameter when it was larger than about 0·06. In the Reynolds-number range 43 < Re < 220, the vortex shedding disappeared for sufficiently large shear parameters. Moreover, in the Reynolds-number range 100 < Re < 1000, the Strouhal number increased as the shear parameter increased beyond about 0·1.

Spring-Arrangement Effect on Flow-Induced Vibration of a Circular Cylinder

2021 ◽  
Author(s):  
Koki Yamada ◽  
Yuga Shigeyoshi ◽  
Shuangjing Chen ◽  
Yoshiki Nishi
Keyword(s):  
Circular Cylinder ◽  
Dynamic Model ◽  
Geometric Nonlinearity ◽  
Water Channel ◽  
Fluid Flows ◽  
Flow Induced Vibration ◽  
Theoretical Evaluation ◽  
Circulating Water ◽  
Linear Dynamic ◽  
Elastically Supported

Abstract Purpose This study elucidated the effect of an inclined spring arrangement on the flow-induced vibration of a circular cylinder to understand if the effect enhances the harnessing of the energy of fluid flows. Method An experiment was conducted on a circulating water channel. A circular cylinder was partially submerged. It was elastically supported by two springs whose longitudinal directions were varied. With the speed of the water flow varied, the vibrations of the circular cylinder were measured. The measured vibrations were interpreted by la linear dynamic model. Results and discussion In a few cases, a jump in response amplitudes from zero to the maximum was observed with the spring inclination at reduced velocities of 6 to 7, whereas gradually increasing response amplitudes were observed in other cases. The inclined spring arrangement achieved greater velocity amplitudes than in cases without spring inclination. A theoretical evaluation of the measured responses indicates that the effect of the inclined springs was caused by geometric nonlinearity; the effect would be more prominent by employing a longer moment lever.

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