Vortex-induced vibration control of 5:1 rectangular cylinder with an attached active splitter plate based on open-loop control method

Vortex-induced vibration (VIV) is a key issue in rectangular cylinder. The splitter plate with a specific length is often mounted behind the bluff body to suppress VIV. However, the still splitter plate is usually unable to completely eliminate VIV. In this study, the splitter plate that can actively vibrate at a certain frequency and amplitude is introduced, and an open-loop control motion equation is established. Computational fluid dynamics numerical simulations were conducted under different control parameters to obtain VIV response, surface wind pressure distribution, and flow field information. The changes in wind pressure distribution under different control parameters were further compared. At the same time, the dynamic mode decomposition method is used to compare the flow field mode evolution and energy distribution under various vibration states of splitter plate to explain the reason why the VIV is suppressed. The results show that the active splitter plate can reduce the fluctuating wind pressure on the structure's surface and suppress or even completely eliminate VIV by introducing new flow modes. The vibration suppression effect is related to the frequency ratio and amplitude. A larger frequency ratio and amplitude can effectively eliminate VIV.