Lift Coefficient Curves for Predicting Response Using Shear7

Vortex-Induced Vibration (VIV) is a complex, non-linear fluid-structure interaction problem with important consequences for offshore risers, tendons and other tubulars. The prevalent approach in the industry is to use semi-empirical formulations to estimate VIV amplitudes, frequencies and the resulting fatigue damage. These semi-empirical techniques estimate VIV response amplitude by considering the balance of power input into the pipe due to vortex-shedding and the loss of power from the pipe due to damping. At the heart of this method are lift coefficient curves, which are used to estimate power input into the pipe. Local lift coefficients are difficult to measure or derive for a flexible pipe and hence most of the lift curves used today have been developed using experiments with rigid cylinders. This paper discusses the development of a new family of lift coefficient curves using experimental data. Results of comparisons between predicted and measured data show the lift curves to effectively predict VIV response.