2016A-OS1-8 Experimental investigation of Vortex-Induced Vibrations (VIV) on long catenary models and subjected to non-uniform velocity profiles, orthogonal to the launch

抄録

This study describe the dynamic behaviors of VIV on catenary lines under non-uniform velocity profiles, confronting the phenomena acting in a vertical configuration. This help understanding VIV in offshore lines. The VIV behavior on rigid cylinders elastically supported, as well as on flexible cylinders with no curvature count with a large literature describing dynamic behaviors and hydrodynamics aspects. However, in the case of long flexible cylinders, there are still more points to be understand, particularly at those conditions closer to the offshore operations -with catenary lines under variable current profile. The catenary models were built by means of silicone tubes fulfilled with steel microspheres leading to achieve a mass ratio of m*= 3.72. An underwater image tracking system and a large number of passive targets along the lines measured displacements along the models. As result, the technique of modal decomposition identified a dynamic behavior quite similar in the catenary model when compared to a vertical configuration, helping the comprehension about the VIV on flexible lines.