Applications of Accurate VIV Response Reconstruction Schemes

Quantifying vortex-induced vibration of long flexible slender structures exposed to ocean currents is critical to their design, analysis, installation and maintenance. These oscillations often driven at high frequencies for extended time may result in fatigue induced damage. Further, these primarily cross-flow oscillations results in an amplification of drag which may lead to possible riser interference issues especially when dealing with inline motions. Developments in instrumentation and installation of data acquisition systems on board marine risers have made accurate measurement of riser responses possible. On the other hand, recent developments in accurately reconstructing the VIV response of the riser using data from these acquisition systems have opened up entirely new array of methods to accurately interrogate, interpret and further improve VIV modeling of such structures. This paper presents with some depth the accurate reconstruction method developed by the authors and their use to identify new basic features of riser VIV. These include in-situ measurements of fatigue damage, identification of new phenomena and their quantification in empirical prediction codes by improving both the empirical models and empirical databases. Examples demonstrating each use of the reconstruction method are applied to data from a model-scale riser experiment.Copyright © 2009 by ASME