Control Of Large Transverse Oscillating Cylinder Wake Flow By Jet Stream

In this paper,wind tunnel experiment method and numerical simulation method are used to study the effect of wake injection on the wake control of large laterally oscillating column.The typical vortex shedding patterns of 2S,2P and P+S were found through the smoke flow display method and numerical simulation method.Representative images of three typical vortex shedding patterns were obtained by high-speed camera and fluent post-processing software.The wind tunnel experiments and numerical simulations will study the diameter D=2.5cm cylinder as the research object and cylinder's dimensionless amplitude A/D=0.3~1.5,dimensionless vibration frequency feD/V?=0~0.25,the effect of wake injection on the wake turbulence of laterally oscillating cylinders was investigated at different amplitudes and vibration frequencies with injection velocity V_e=0-15 m/s in a uniform of 1200 Reynolds number.First,through the smoke line experiment and the hot line experiment,the 2S mode was fo und in the dimensionless amplitude A/D=0.5 and the dimensionless vibration frequency feD/V?=0.107.The 2P mode was found in dimensionless amplitude A/D=1 and dimensionless vibration frequency feD/V?=0.154.In the dimensionless amplitude A/D=1.5 and dimensionless frequenc feD/V?=0.193,the P+S mode was found,and the jet flow at different speeds was added to observe the wake suppression effect.When the speed is in the effective speed range,the wake suppression effect is obvious,and the power spectrum peaks.There was also a decline of more than 50%.After the injection speed was too high,the peak value increased but the basin appeared confusing.Two kinds of vortex shedding modes,2S,2P and P+S,were found by numerical simulation method under the same conditions as the wind tunnel experiment.The results were in good agreement with the experimental results.The jet flow with different velocity was used to suppress the wake flow.The vortex shedding pattern changes significantly.Within a certain speed,the number and size of vortices are significantly reduced.When the injection velocity is too large,negative effects are produced,the river basin is in a state of chaos,and the velocity power spectrum of uncontrolled and injected jets is analyzed.In the figure,within a certain speed range,the speed power spectrum is reduced by more than 50%compared with no control.In general,the 2S mode and the 2P mode have a greater suppression effect in adding the jet flow compared to the injection.Airflow has a relatively weak suppression effect on the wake of P+S mode.Thirdly,the vortex shedding modes with different amplitudes and different vibration frequencies were classified.Some new vortex shedding modes were found.The graphs of the variation of vortex shedding modes with vibration frequency and injection velocity at different amplitudes and power spectrum mean change diagram were drawn.