Active control of vortex-induced vibration of a circular cylinder by using the oscillatory plate immersed in the cylinder wake at low Reynolds number

As a typical fluid-solid interaction problem, vortex-induced vibration (VIV) is common in engineering, so it is vital to study its control mechanism. Numerical simulations of the active control of VIV of a cylinder are carried out in this study. The splitter plate with harmonic oscillation is used as the control device for the dynamic response of the cylinder. The displacement response, lift and drag coefficient, vibration frequency of the cylinder, energy efficiency of control strategy, and characteristics of the flow field are widely analyzed to reveal the physical mechanism of the control system. The results show that the displacement response of the cylinder can be limited in a small range by the control without feedback in most cases except for high reduced velocity. In addition, the control strategy can be changed through feedback control to keep much superior control effects at the high reduced velocity. The oscillatory splitter plate delays the vortex shedding of shear layers generated on the cylinder, the wake vortices with opposite sense of rotation are paralleled with the streamwise direction, and crosswise distances of them are reduced. Thus, the lift on the cylinder is greatly decreased due to the modification of the flow pattern induced by the oscillatory splitter plate.