Flow Control for Vortex Shedding of a Circular Cylinder Based on a Steady Suction Method

In this study, a suction flow control method was employed to suppress the vortex shedding of a circular cylinder based on a multi-point suction type. A digital particle image velocimetry (PIV) system was used to conduct detailed flow field measurements un

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Abstract In this study, a suction flow control method was employed to suppress the vortex shedding of a circular cylinder based on a multi-point suction type. A digital particle image velocimetry (PIV) system was used to conduct detailed flow field measurements under different suction flow control conditions with simultaneously measuring the pressure distribution on the test models. Five steady suction flow rates of 20, 40, 60, 80, and 95 L/min were employed in the testing. The suction control effects were investigated under an angle of 90.0° of the suction holes; the effects of the suction flow control along the axial direction of the test model were investigated. The mean and fluctuating pressure coefficients, the lift and drag coefficients, the mean velocity fields of the circular cylinder, and the mean velocity profiles in the wake under the suction flow control were then analyzed. The results indicated that the steady suctions exhibited excellent control effects and could dramatically reduce the fluctuations of lift coefficients and the averages of the drag coefficients and distinctly suppress the alternating vortex shedding (changing into symmetric mode). The control effects of the suction along the axial direction of the model are not uniform and the control effects are improved from the section without suction to the suction section.

1 Introduction As key components of cable-stayed bridges, inclined cables often vibrate under wind, rain, and traffic loads, such as the vortex-induced vibration (VIV) (Zuo et al. 2008) and rain-wind induced vibration (RWIV) (Hikami and Shiraishi 1988). W.-L. Chen (&)  H. Li School of Civil Engineering, Harbin Institute of Technology, Harbin, China e-mail: [email protected] W.-L. Chen  H. Hu Department of Aerospace Engineering, Iowa State University, Ames, USA

Y. Zhou et al. (eds.), Fluid-Structure-Sound Interactions and Control, Lecture Notes in Mechanical Engineering, DOI: 10.1007/978-3-642-40371-2_53, Ó Springer-Verlag Berlin Heidelberg 2014

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Frequent wind-induced vibrations which are often induced by the alternating vortex shedding of the stayed cables may induce fatigue damages to the cables, so it is necessary to suppress the vortex shedding of the cables to mitigate the vibration. Suction flow controls were also widely used to suppress the flow separation of circular cylinders (Fransson et al. 2004; Patil and Ng 2010) by tests or CFD numerical simulations. Patil and Ng (2010), Fransson et al. (2004) found that the continuous porosity could lead to a drag reduction, suppress the spanwise vortices formation, reduce the velocity fluctuation level, eliminate the oscillation of the lift, and delay the separation resulting in a narrower wake width. In present paper, a steady suction flow control method is adopted to suppress the vortex shedding of a circular cylinder based on a multi-point suction type. Further details and comprehensive study on this method to control the vortex shedding of a circular cylinder will be submitted as a journal pa