By applying an overlapping mesh, a vortex-induced vibration (VIV) model was constructed and the effect of several key factors on VIV: mass ratio m*, Reynolds number Reand, reduced velocity Vr = U/fND was investigated. By assuming A/D = f(m*, Re, Vr), parameter analysis was taken about influence of the three parameters on A/D, and especially, the two terms of Clwhich is in phase with velocity (Clv) or is in phase with acceleration (Cla) are computed respectively, the contours of them were plotted. It was found that the maximum crossflow amplitudes are 3~6 times of those in in-line direction. Response and fluid forces achieve their peak values as Vr is around 6~7 and Re is about 2.2×104, inside the so-called concentrate area, Re has a linear influence on A/D, but outside, Re has little effect on them. On the other hand, Vr basically has linear influence on Clv, Cla, while Re has slight effect on them.
Vortex-induced vibrations (VIV) are important issues in many engineering fields. The prediction of responses due to VIVs is still a challenging work for engineers however, because of the complexity of interaction between fluid and structure (FSI). Griffin (1972) carried out both self-excited and sinusoidally forced oscillations under nearly similar conditions. The free vibrations exhibited amplitude and phase modulations at the same average amplitude. The average velocities in the wake were quite similar, but their instantaneous values exhibited expected discrepancies. Moe and Wu (1990) report an extensive program of free and forced vibration tests in a uniform current. Traditionally, VIV was predicted by using wake oscillators (mainly van de Pol oscillator) or by adopting Morison's Equation to calculate the fluid forces, these models are too simple to account for the underlying complexity of fluid structure interaction (FSI).