Suppression Effect Of Double Element On Vortex Shedding From A Lateral Oscillating Circular Cylinder

Vortex-induced Vibration is damaged to ocean and civil engineering,and it’s significant to study the control of vortex shedding from a forced oscillating cylinder.In this paper,experiments and numerical simulation are used to study the control of vortex shedding from a lateral oscillating circular cylinder.Mainly job:a cylinder with diameter D=2.5 cm is taken as the research object in the condition of oscillating amplitude A/D between 0.3 and 2.0,frequency f_eD/V_∞ between 0 and0.25,and Reynolds numberRe=V_∞D/v=1200.Two strip elements of width b/D=0.32 are used and set in the wake to influence the vortex shedding,the suppression degree is evaluated,the control parameters are transverse distance X/D and longitudinal distance Y/D from cylinder to strip.Mainly result:1.the 2S mode vortex shedding was found at oscillating amplitude A/D=0.5,frequencyf_eD/V_∞=0.143;2.the P+S mode vortex shedding was found at oscillating amplitude A/D=1.5and frequencyf_eD/V_∞=0.2.The results of the experiment and the simulation are compared to ensure the consistency.Mainly conclution:the main peak value in the averaged spectrum of multi-points fluctuating velocities can be used to represent vortex strength,the contours of vortex strength is figured out on the plane of strip position.1.The experimental results show that vortex strength can be reduced by 30%of 2S mode and 36%of P+S mode if the strip is set at places in a relatively large region.Under the simulation condition,the vortex strength can be reduced by 50% of 2S mode and 60%of P+S mode.2.We find that with the change of strip position in the area 0.4≤X/D≤4,0.4≤Y/D≤4.4,the P+S mode vortex shedding is changed to 2P mode,T mode and T+S mode,the contours of vortex mode is figured out on the plane of strip position;The 2S mode is not changed by the strip in the studied ranges of X/D and Y/D.