Further Investigations on Vortex Self Induced Vibration (VSIV)

An experimental facility has been designed to study 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 study aims to analyze the vortex self induced vibration (VSIV) phenomena, which occurs for instance with Steel Catenary Risers (SRCs) the deep offshore connected to floating platforms. These vibrations occur even in the absence of a current. 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 tests were carried out with Keulegan-Carpenter numbers equal to 10 and 20 and for several exciting frequencies. The vertical trajectories of the VSIV motion were then classified based on its different configurations such as oval-shape, eight-shape and etc. Different ranges of reduced velocities were also considered. The amplitude and frequency of transversal motion and also the forces calculated.