Suppression of Vortex Shedding from a Circular Cylinder by using a Suction Flow Control Method

An experimental study was conduct to suppress the vortex shedding from a circular cylinder by using a suction flow control method. The suction flow control was accomplished using two suction holes located on the test cylinder model at an angle of 90.0 degrees in relation to the oncoming flow direction. In addition to measuring the pressure distributions around the test model, a high-resolution digital particle image Velocimetry (PIV) system was used to conduct detailed flow field measurements to quantify the transient shedding behavior of the unsteady vortex and turbulent flow structures in the wake of the test cylinder model under different suction flow control conditions. The effectiveness of the vortex shedding suppression using the suction flow control method was evaluated based on the quantitative measurement results, which include the mean and fluctuating pressure coefficient distributions around the test cylinder model, the lift and drag coefficients of the test cylinder model with and without suction flow control, the instantaneous velocity and vorticity fields, the mean velocity and turbulence kinetic energy distributions around the cylinder model, and the mean velocity profiles in the wake of the test model under different suction flow control conditions. The measurement results of the present study revealed that the suction flow control method exhibited excellent performance in suppressing the alternative vortex shedding from the circular cylinder model (i.e., change the alternative vortex shedding mode into symmetric mode). As a result, the fluctuations of the lift coefficients and drag coefficients of the cylinder model were found to be reduced dramatically by using the suction flow control method.