Numerical Simulation Study on the Hydrodynamic Performance of Circular Oscillating Buoy Wave Energy Generation Device

Wave energy, as an environmentally friendly and sustainable energy source, possessed substantial development potential and held significant application value in the domain of new energy technologies. To enhance the capture efficiency of wave energy, a novel oscillating buoy-type wave energy generation device was designed. Computational Fluid Dynamics (CFD) method was applied to numerically simulate the hydrodynamic performance of the wave energy generation device, providing a theoretical foundation for optimizing the design of wave energy generation devices. Firstly, a numerical wave tank was established, and the effectiveness and accuracy of the numerical wave tank were validated. Secondly, a hole was made at the center of the circular oscillating buoy, and the CFD software Star-CCM+ was used to numerically simulate the hydrodynamic performance of the buoy with openings. This paper considered different aperture sizes of the buoy under two sets of different conditions, including 200mm, 300mm, 400mm, 500mm, 600mm, 700mm and 800mm. Based on the numerical simulation results, through statistical analysis, the oscillating force and oscillating motion amplitude data of the oscillating buoys with different apertures were obtained, covering the maximum, minimum, average, variance, and mean deviation values for each aperture size of the buoys. Thirdly, the vorticity of eight typical oscillating buoys was compared and analyzed in this study, thereby investigating the inner mechanism between force and vorticity. Through statistical analysis of the hydrodynamic performance of a circular oscillating buoy with different aperture sizes, the following conclusions can be drawn: Under the same operating conditions, the oscillating buoy with a 300mm aperture exhibited the largest maximum oscillating force, while the buoy with an 800mm aperture demonstrated the smallest maximum oscillating force. As the aperture size increased, the oscillating force and amplitude generally exhibited a fluctuating decrease. Further analysis using vorticity plots revealed that the buoy with a larger aperture size exhibited more vorticity, indicating greater energy dissipation and smaller oscillating force. Conversely, the buoy with a smaller aperture size exhibited less vorticity, suggesting less energy dissipation and therefore larger oscillating force.