Numerical study on the improvement design of the oscillating buoy wave energy converter

The oscillating buoy wave energy converter (OBWEC) is a popular and widely used wave energy converter (WEC) due to the simplicity of its structure and its strong adaptability. In this paper, the "Haiyuan No. 1'' OBWEC is taken as the research object, in which the buoys adopt heave mode of motion. In order to further enhance the hydrodynamic performance of the buoys, an improved scheme with longitudinal swing motion is proposed through theoretical analysis for the buoy. A 2D numerical wave tank (NWT) model based on the RANS equation is established by using CFD software. The numerical model is applied to compare and analyze the hydrodynamic performance differences of the buoy under two different motion forms: heaving and longitudinal swing, and the consistency of the numerical results is validated by the experimental data under regular waves. Finally, the irregular wave data obtained during the sea trial of the "Haiyuan No. 1'' OBWEC is used to numerically simulate the two buoys. The results show that the buoy with longitudinal swing motion is more effective in improving the hydrodynamic performance compared to the buoy with heave motion, in both regular and irregular waves. The conclusions of this paper can serve as a guide to improve the design of the hydrodynamic performance of the buoy.