Suppression Of The Wakes Downstream Of A Transversely Oscillating Cylinder With Large-Amplitude

In this paper,the wind tunnel experiment and numerical simulation method were used to study the control of large-amplitude transverse oscillating cylinder wake.The experiment and the numerical simulation method were used to find 2P,P+S mode(P represents pair,S represents single),which was the most representative of the different modes.The cylinder was used as the research object,its diameter D=2.5 cm,the Reynolds number wasRe=V_?D?=1200,the non-dimensional frequency of oscillation wasf_eD_?V=0~0.25,and the non-dimensional Amplitude ratio was A D=0.3~1.5,Through the smoke line and the hot line experiment,the model of the vortex shedding of 2P and P+S was found.The 2P vortex shedding mode condition was A D=1,f_e D V_?=0.143,when single controller was located in a effective zone,the vortex shedding characteristics on both sides of the cylinder became irregular,the whole flow vortex chaos,the average power spectrum peak was reduced by more than 50%.The suppression of vortex shedding with double controllers do not better than single one,even worse.The P+S vortex shedding mode was found under the condition of A D=1.5,f_e D V_?=0.192 and it was controlled by a stationary narrow strip.it had a smaller effective area.Second,the numerical simulation method was used to find the typical working conditions of different vortex shedding modes,The results were in good agreement with the smoke-wire test.The narrow strip(b/D=0.32)was used for the suppression of the vortex shedding from a circular cylinder oscillating.In the P+S mode,Control effect was remarkable when the controller was placed in a certain region called effective zone.the suppression of vortex shedding with double controllers do not better than single one,even worse.The results shows that fluctuating drag and lift of cylinder can be greatly reduced,the average power spectrum peak is reduced by more than 50%when the controller is placed in effective zone.the suppression of vortex shedding with double controllers do not better than single one,even worse in 2P mode.No significant difference in suppression effect of different width controllers.The numerical simulation results are better than the wind tunnel experiment.