Investigation on 3-D characteristics of flow around a yawed and inclined circular cylinder

Yeo, Dong Hun; Jones, Nicholas P.

doi:10.1016/j.jweia.2008.02.040

Cited by 51 publications

(22 citation statements)

References 5 publications

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“…Further experimental investigations had been carried out by Shirakashi et al (1984), Lourenco et al (1992) and Hayashi and Kawamura (1995). Moreover, numerical simulations on yawed cylinders had also been carried out (Kawamura and Hayashi, 1994;Kaneko and Kawamura, 2002;Lucor and Karniadakis, 2003;Marshall, 2003;Thakur et al, 2004;Yeo and Jones, 2008;Vakil and Green, 2009;Zhao et al, 2009). Kaneko and Kawamura (2002) used direct numerical simulation (DNS) for flow past a yawed circular cylinder at subcritical Reynolds number of 1000 and found that the Independence Principle fails for the cylinder at large yaw angles.…”

Section: Introductionmentioning

confidence: 99%

Investigation of turbulent flow past a yawed wavy cylinder

Lam

Lin

Zhang

et al. 2010

Journal of Fluids and Structures

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Section: Introductionmentioning

confidence: 99%

Investigation of turbulent flow past a yawed wavy cylinder

Lam

Lin

Zhang

et al. 2010

Journal of Fluids and Structures

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“…This knowledge is of both fundamental and practical importance to our understanding of the physics of vortex shedding, three dimensionality of the velocity and vorticity fields, the change in the coherent structures, and the vortex dislocation in the yawed cylinder wake at subcritical Reynolds numbers. A 3D detached eddy simulation was conducted by Yeo and Jones 26 for three different spanwise aspect ratios ͑L / d = 10, 20, and 30, where L and d are the length and diameter of the cylinder, respectively͒ using both slip wall and periodic wall conditions for the spanwise wall boundary conditions. They found that the slip wall spanwise boundary conditions influenced the vortex flow structures significantly over quite a large spanwise range from the upper end of the cylinder, which was not the case if the periodic spanwise wall boundary conditions were used.…”

Section: Introductionmentioning

confidence: 99%

“…It is also found by these authors that the vortices right behind the cylinder are convected not only in the incoming flow direction, but also in the cylinder axial direction, which is consistent with that of Yeo and Jones. 26 The enhanced spanwise velocity as ␣ is increased helps to dislocate the large-scale structures and enhance the three dimensionality of the flow, resulting in dispersion of the large-scale vortical structures. This result may indicate that with the increase in ␣, the intermittency of the vortex structures increases, which can be revealed also by the probability density function ͑pdf͒ of the vorticity signals.…”

mentioning

confidence: 99%

Three-dimensional vorticity measurements in the wake of a yawed circular cylinder

et al. 2010

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Using a phase-averaged technique, the dependence of the wake vortical structures on cylinder yaw angle ␣ ͑=0°-45°͒ was investigated by measuring all three-velocity and vorticity components simultaneously using an eight-hot wire vorticity probe in the intermediate region ͑x / d =10͒ of a yawed stationary circular cylinder wake. For all yaw angles, the phase-averaged velocity and vorticity contours display apparent Kármán vortices. It is found that when ␣ Յ 15°, the maximum coherent concentrations of the three vorticity components do not change with ␣. However, when ␣ is increased to 45°, the maximum concentrations of the coherent transverse and spanwise vorticity components decrease by about 33% and 50%, respectively, while that of the streamwise vorticity increases by about 70%, suggesting that the strength of the Kármán vortex shed from the yawed cylinder decreases and the three dimensionality of the flow is enhanced. The maximum coherent concentrations of u and v contours decrease by more than 20% while that of w increases by 100%. Correspondingly, the coherent contributions to the velocity variances ͗u 2 ͘ and ͗v 2 ͘ decrease, while that of ͗w 2 ͘ increases. These results may indicate the generation of the secondary axial vortices in yawed cylinder wakes when ␣ is larger than 15°. The incoherent vorticity contours ͗ xr 2 ͘ are stretched along an axis inclining to the x-axis at an angle ␤ in the range of 60°-25°for ␣ = 0°-45°. The magnitudes of ͱ͗ xr 2 ͘ ‫ء‬ and ͱ͗ yr 2 ͘ ‫ء‬ through the saddle points are comparable to the maximum concentration of the coherent spanwise vorticity z ‫ء‬ at all cylinder yaw angles, supporting the previous speculation that the strength of the riblike structures in the cylinder wake is about the same as that of the spanwise structures, even in the yawed cylinder wakes.

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“…Macdonald also confirmed that instances of "dry" vibrations at low wind speed have been reported, probably at sub-critical Reynolds numbers, where the oscillations are in a transverse or across-wind direction, which are not explainable by the quasi-steady theory. Recent numerical research from Yeo and Jones (2008) investigates the flow past a dry inclined cable at sub-critical Reynolds numbers. The results illustrate how swirling eddies are generated alternately from both sides of the cylinder but also move along the cylinder thus delaying the vortex shedding.…”

Section: Discussion : Key Research Themes and Future Research Directionsmentioning

confidence: 99%

New developments in rain–wind-induced vibrations of cables

Taylor¹,

Robertson²,

Wilson³

et al. 2010

Proceedings of the Institution of Civil Engineers - Structures

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On wet and windy days, the inclined cables of cable-stayed bridges can experience large amplitude, potentially damaging oscillations known as rain–wind-induced vibration (RWIV). RWIV is believed to be the result of a complicated non-linear interaction between rivulets of rain water that run down the cables and the wind loading on the cables from the unsteady aerodynamics; however, despite a considerable international research effort, the underlying physical mechanism that governs this oscillation is still not satisfactorily understood. An international workshop on RWIV was held in April 2008, hosted at the University of Strathclyde. The main outcomes of this workshop are summarised in the paper. A numerical method to investigate aspects of the RWIV phenomenon has recently been developed by the authors, which couples an unsteady aerodynamic solver to a thin-film model based on lubrication theory for the flow of the rain water to ascertain the motion of the rivulets owing to the unsteady aerodynamic field. This novel numerical technique, which is still in the relatively early stages of development, has already provided useful information on the coupling between the external aerodynamic flow and the rivulet, and a summary of some of the key results to date is presented.

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Investigation on 3-D characteristics of flow around a yawed and inclined circular cylinder

Cited by 51 publications

References 5 publications

Investigation of turbulent flow past a yawed wavy cylinder

Investigation of turbulent flow past a yawed wavy cylinder

Three-dimensional vorticity measurements in the wake of a yawed circular cylinder

New developments in rain–wind-induced vibrations of cables

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