Insight into Data from Forced Oscillation Tests in Prediction of VIV of Flexible Risers

摘要

Recently, many efforts have been devoted to the prediction of vortex-induced vibration of marine risers. Many empirical tools have been developed which are based on data from forced oscillation tests of rigid cylinder sections. Based on the discussion on the relationship of free and forced vibration experiments of circular cylinders, this paper put forward a prediction model for VIV of a slender riser in which fluid force coefficients obtained in forced oscillation tests are applied more directly than other similar models. The capability of the proposed model is testified with model tests of risers in stepped and in sheared currents. In particular, the added mass effects are well accounted for with this model. The limitations of such a kind of methods based on forced oscillation tests are also pointed out.