Analysis of PIV Tests Results of the Vortex Self Induced Vibration (VSIV) of a Cylinder

The Vortex Self Induced Vibration (VSIV) of cylinders is a phenomenon which occurs in the nature with devices such as Steel Catenary Risers (SRCs) in the deep offshore connected to floating platforms. The devices oscillate transversely due the own vertical motion. This is a currentless (therefore different form VIV) problem. To gain more insight into the nature of VSIV problem, an experimental apparatus was constructed which measure the transversal and response associated with vortex-induced vibration of a totally submerged horizontal cylinder hang on horizontally elastic support under the influence of vertical harmonic oscillating motion. The experiments were conducted in a tank at the LOC/COPPE/UFRJ (Laboratory of Waves and Current of COPPE, Federal University of Rio de Janeiro). The VSIV phenomena of the cylinder in different exciting amplitudes and exciting frequencies could generate different vertical trajectories of VSIV motion such as oval-shape, eight-shape and etc. This paper aims to describe the behavior of the flow around the cylinder during the VSIV motion based on the PIV tests on VSIV motion for different Keulegan-Carpenter numbers and for several exciting frequencies.