A novel vortex-induced vibration model for a circular cylinder in the vicinity of a plane wall

Abstract

A novel vortex-induced vibration (VIV) model is proposed to predict the transverse responses of an elastically mounted circular cylinder in the proximity of the wall. Firstly, flow characteristics and hydrodynamic loads on a near-wall stationary circular cylinder are summarized and analyzed based on the existing experimental results, and then the Strouhal shedding frequency and the empirical correlations of the mean lift coefficient and oscillating lift coefficient are established. Subsequently, by introducing the empirical correlations of fluid loads to the equations of structure vibration, a novel VIV model for the near-wall circular cylinder is proposed to describe more precisely the effect of the plane wall. The accuracy, stability, and adaptability are validated by employing experimental VIV results. Compared to existing models, the novel model has advantages in achieving acceptable accuracy in various scenarios. Finally, using the proposed VIV model, the dynamic features of a near-wall circular cylinder to the reduced velocity and gap ratio are studied in detail, including the time-averaged displacements, lock-in regime, maximum amplitude, and dominant frequency. The results obtained are valuable for understanding the VIV characteristics of the near-wall cylinder, and the semi-empirical VIV model proposed could be applied in engineering prediction in the future.