A prediction technique for the transverse vortex-induced oscillations of tensioned risers

Abstract

In this paper, a model for the prediction of the vortex-induced transverse oscillations of tensioned risers is proposed. The model, based on the peak amplitudes of the oscillations recorded for cylindrical bodies in a uniform current, has been extended to multimodal oscillations in a sheared flow condition through a modal priority technique. The difference between this model and other similar ones lies in the following features: the hydrodynamic damping, which has been introduced in a more general form without ‘a priori’ approximations; the modal priority, which is based on the local amplitudes of the active vibration modes, rather than on their frequencies. Some comparisons with experimental and numerical results available in the literature are presented and discussed.