Flow control over a horizontal cylinder by symmetrically distributed flexible body

The flow control over a horizontal cylinder using a flexible body was experimentally investigated in this study. The upper and lower parts of the symmetrical flexible body were attached to the submerged cylinder model in a laboratory wave–current tank. Particle image velocimetry (PIV) was used to analyze the transient interaction between the flow field and the flexible body. By varying the attachment position, length and thickness of the flexible body, the load–reduction effect on the structure was systematically examined. The experimental results demonstrate that the flexible body significantly reduces the lift under both uniform currents and wave–current conditions. The control mechanism was revealed through fluctuations in the pressure distribution and the unsteady flow characteristics. The flexible body exhibits distributed deformation and reaches its maximum curvature during the formation of the wake vortex, with a phase-lagged response to the vortex action. Optimal flow control performance occurs under an appropriate parameter combination of the flexible body. This research provides experimental evidence supporting the feasibility of using flexible structures to modulate wake dynamics for load reduction in marine engineering applications.