Vortex induced vibration of a circular cylinder through its slow phase dynamics: theory vs. experiments

The wake-oscillator model of Tamura for Vortex induced vibration (VIV) under free vibration conditions is deeply analysed for parameters identification through a perturbation methods analysis. In the slow phase model of VIV, a simple analytic solution for the amplitude of motion and phase is derived. The model is proved to be accurate for the estimation of the maximum amplitude and lock-in range. Results show that the phase between the displacement and the wake variable plays a key role in the lock-in mechanism and needs to be measured experimentally in further studies. The proposed parameter identification is direct thanks to analytical expressions and will be used in further experiments involving other shapes and tandem cylinders.