An experimental study on flow-induced vibration of a flexible cylinder with an attached flexible splitter plate

Flow-induced vibration of a flexible circular cylinder with an attached flexible splitter plate is studied, experimentally. Dynamic response of the system was studied for three different splitter plate widths of 1D, 2D, and 3D, where D is the cylinder's diameter. At a low reduced velocity range at which the bare cylinder without a splitter plate experienced oscillations at its first two bending modes, up to 70% reduction in amplitudes of oscillations was observed for the cylinder with the splitter compared to those of the bare cylinder. At this region, frequencies of oscillations monotonically increased from values close to 0.5 times to twice the first bending natural frequency. At a higher reduced velocity range, amplitudes of oscillation increased for all three cases, but they still stayed smaller than those of the bare cylinder for splitter widths of 1D and 2D. For the case of splitter width of 3D, the amplitudes of oscillations monotonically increased, exceeding those of the bare cylinder with maximum amplitudes as large as 2.6 times those of the bare cylinder's oscillations. While the response exhibited mainly mono-frequency oscillations at this range for the splitter plate width of 1D, multi-frequency oscillations dominated the response for wider splitter plate cases.