Influence of Axial-Flow Turbulence Intensity on Fluid-Structure Interaction for a Flexible Cylinder

This work aims to investigate experimentally the fluid-structure interaction FSI for a flexible cylinder subjected to axial turbulent flows. Two configurations are considered; a solitary flexible cylinder with simple support ends and is free to vibrate in the transverse direction, another configuration is a non-flexible cylinder which installed parallel and adjacent to the flexible cylinder in various cylinder centre-to-centre pitch P * (=P/D, where D is the diameter of the flexible cylinder). Investigation on the effect of axial-flow turbulence intensity T u at 0.7 and 2.9% on the FSI for the two configurations over a range of freestream velocity U∞ (0.19–2.14 m/s) is performed by means of simultaneous measurement of flexible cylinder vibration and velocity field adjacent to the cylinder. We found that T u has a strong effect on the flexible cylinder vibration in both configurations. At high ∞ and T u , we observed substantial interaction of flow structures between cylinders which provokes the buckling of the flexible cylinder at a lower critical velocity compared with its counterpart of a solitary cylinder.