A novel Wake Oscillator Model for simulation of cross-flow vortex induced vibrations of a circular cylinder close to a plane boundary

This paper presents a novel Wake Oscillator Model for predicting Vortex-Induced Vibration (VIV) of a circular cylinder close to a plane boundary. The innovation lies in its extension of the classic Van der Pol equation by introducing an additional nonlinear term and two empirical coefficients to account explicitly for the effects of the gap ratio and mass ratio. The model parameters are calibrated against available experimental data and a number of validation tests are then performed. Despite the intrinsic limitations of the Wake Oscillator Model approach, the simulation results demonstrate that the predicted variations of vibration amplitudes with the reduced velocity are broadly consistent with the experimental data and the model is also capable of capturing the different vortex shedding modes. With further refinements, the proposed modelling approach is expected to provide an efficient engineering means to predict both the overall variation trend and maximum value of vibration amplitude of a circular cylinder close to a plane boundary over the full range of reduced velocities.