Suppression Of Vortex Shedding On Rotating Oscillating Plate By The Wind Fairing

The 5:1 rectangular column is regarded as the representative of the general bridge deck geometry,and its simplified model can be used to study wind vibration control.As a common flow control device,the wind fairing can reduce drag and increase aerodynamic stability of rectangular plate,but the control mechanism of the control device on the forced oscillation cylinder is still lacking.The effects of control devices on vortex shedding of rectangular plate wakes were studied by applying forced vibration to segment models and edge-shaped symmetrical wind fairing to the front of the experimental model.The power spectrum of the hot-wire velocimetry experiment shows that the vortex shedding frequency changes obviously after the control is applied,and the peak of the power spectrum decreases obviously when the critical frequency feD/V∞ is less than 0.05.The frequency-locked,non-frequency-locked and harmonic frequency-locked region of vortex shedding with wind fairing are found.The vorticity field obtained by the unsteady equation SST k-ω is in good agreement is in good agreement with the smoke line flow experiment,and five vortex shedding patterns are found,which are 2S(4)mode,2S2 mode,2P mode,2T mode and 2S3 mode respectively.And the instantaneous streamline field and pressure field of numerical simulation reveal the vortex separation and the change of low pressure region near the plate surface.The unsteady equations SST k-ω reveal the vortex separation near the surface of the plate well.The time-domain mean and root mean square values of aerodynamic coefficients are analyzed,the amplitude and frequency range of vortex shedding can be suppressed effectively by the wind fairing.The results of flutter derivative analysis show that the lift phase shift is independent of the amplitude,but negatively correlated with the vibration frequency.The torque phase shift is more significantly affected by the amplitude.