Multi-degree-of-freedom hydrodynamic performance study of finned floats

Objective To optimize the energy capture efficiency of a rocker-type wave energy converter, the effects of the platform pillar wave diversion scheme and shape of finned floats on energy capture are studied.

Methods First, a hydrodynamic model of float motion is established. Next, the hydrodynamic characteristics of different finned floats are calculated using AQWA software and analyzed under different platform pillar wave diversion schemes, different frequency domain parameters such as added mass, radiation damping, wave excitation force and response amplitude operator (RAO), and different time domain parameters such as displacement, velocity, acceleration and excitation force. Finally, the energy-capture width ratios of different finned floats under different platform pillar wave diversion schemes are investigated.

Results The results show that different platform pillar wave diversion schemes have little effect on the frequency domain parameters of the finned floats or the float motion displacement of time domain parameters, but a large effect on the motion period. Energy capture is optimal at a fin angle of 100° under the double-pillar wave diversion scheme.

Conclusions Based on the proposed numerical simulation model, the hydrodynamic response of multi-degree-of-freedom finned floats in wave motion can be simulated accurately, providing useful references for the optimized design of the float shape for oscillating float-type wave energy generation platforms.