Flow-induced vibration control of a circular cylinder by using flexible and rigid splitter plates

Abstract

Flow-induced vibration (FIV) control of a circular cylinder by using a flexible splitter plate attached to the rear stagnation point is experimentally investigated. The rigid splitter plate is also applied to highlight the unique feature of the flexible splitter plate. A platform has been designed to ensure that the cylinder can only vibrate in the transverse direction. The Reynolds numbers based on the cylinder diameter and the free-stream velocity are in the range of 1680–8720. When a flexible or rigid splitter plate is attached, the vibration response of the circular cylinder is different. The vortex-induced vibration (VIV) and galloping are both observed for the rigid splitter plate cases. Though the vibration amplitude in the synchronization region is reduced by the rigid splitter plate, it increases linearly with the reduced velocity at large reduced velocities. However, the flexible splitter plate with a streamwise length greater than one cylinder diameter performs well in suppression of the vibration, and the reduction in the maximum amplitude reaches about 91% compared with the natural case. The flow pattern in the wake is changed by the splitter plate. The interaction between upper and lower shear layers is reduced, especially in the near-wake region. The shear layers shedding from the cylinder do not alternately reattach on the tip of the flexible splitter plate, thus, the galloping does not occur.