Experimental investigation of the suppression of vortex-induced vibration in four cylinders arranged in a square under different spacing ratios

Abstract

A vortex-induced vibration (VIV) is a typical flow-structure interference phenomenon that causes an unsteady flow pattern owing to vortex shedding at or near the structure’s natural frequency, leading to resonant vibrations. VIVs can cause the failure of marine risers owing to premature fatigue, because of which a growing amount of research has attended to them. To investigate the effects of suppressing the VIV of splitter plates on a square array of cylinders under different spacing ratios, cylinders undergoing VIV in a flow with a Reynolds number ranging from 3300 to 6750 were experimentally studied in this paper. The results show that the splitter plate can suppress cross-flow (CF) vibrations as well as in-line flow (IF) vibrations in the cylinders. For cross-flow vibration, the suppression effects of the splitter plate on the upstream cylinders were at their maximum at $$S/D = 5$$ while the effects on downstream cylinders reached this at $$S/D = 6$$, where $$S/D$$ refers to the ratio of the distance between the centers of cylinders to its diameter. For in-line flow vibrations, the effects on upstream and downstream cylinders all reached the maximum at $$S/D = 4$$. The vibrational frequency of the cylinder with splitter plate was also lower than that of the bare cylinder in the flow.