This study reports an experimental investigation on the flow-induced vibration (FIV) of
elastically mounted rectangular cylinders with high-side-ratio in free-stream flow. The side
ratio (σ), defined as the ratio of the cross-flow side width (h) to the streamwise side width (b)
of the cylinder, namely σ= h∕ b, was varied from 2.0 to 5.0. The fluid–structure system was
modelled using a low-friction air-bearing system in conjunction with a free-surface water
channel facility. The structural vibration was characterised over the reduced velocity range of …