Numerical Investigation of Flow-Induced Vibration for Cylinder-Plate Assembly at low Reynolds Number

The transverse flow-induced vibration (FIV) of an elastically-supported cylinder-plate assembly (viz., a rigid splitter-plate attached to the downstream side of a circular cylinder) with a low mass ratio of 10 and zero structural damping is investigated using numerical simulations at a Reynolds number of 100. The structural oscillations and characteristics of the flow around the structure are analyzed in terms of the vibration characteristics and the fluid forces as a function of the plate length L-SP and the reduced velocity U-r. These investigations involve a wide range of plate lengths L-SP/D = 0-4 (where D is the cylinder diameter) over an extensive span of reduced velocities U-r = 2-30. For L-SP/D <= 0.5, self-limiting oscillations are induced in the assembly-these oscillations correspond to either a vortex-induced vibration (VIV) or an integrated VIV-galloping response. For L-SP/D >= 0.75, the amplitude response is no longer self-limiting in the sense that the oscillation amplitude increases linearly with increasing U-r-these oscillations correspond to either a strongly correlated VIV-galloping regime (for L-SP/D = 0.75), or two clearly separated regimes: namely, a VIV regime with small-amplitude oscillation and a non-limiting galloping regime (for L-SP/D > 0.75).