Performance analysis of the oscillating-body wave energy converter with a novel bistable mechanism under irregular wave conditions

The present study investigates the application of a novel nonlinear bistable mechanism to the oscillating-body wave energy converter (WEC) under irregular wave conditions. The numerical simulations of the linear and nonlinear WEC devices are performed with the hydrodynamic analysis software AQWA and coding program MATLAB. Firstly, the hydrodynamic model of the WEC buoy is validated. Then, a parametric analysis on the energy conversion of the nonlinear WEC is conducted concerning the properties of power take-off (PTO) devices and wave parameters. The findings reveal that each parameter has a significant influence on the nonlinear WEC’s performance under irregular waves. Therefore, the parametric study should be carried out to determine the device parameters, which ensures that the nonlinear WEC outperforms the linear WEC under the specific environmental conditions. Moreover, it is found that the WEC with the proposed bistable system could absorb more power at the low-frequency region, which addresses the issue of efficiently capturing low-frequency wave energy.