Parametric analysis on float geometries of a bistable two-body point absorber wave energy converter

The data and code are associated with a scientific research on a two-body point absorber wave energy converter (WEC) equipped with a bistable mechanism. And the data and code can be edited by Matlab. In this reasearch, the power take-off (PTO) is simplified as a linear model for the focus on the coupling mechanism between a bistable system and multi-body hydrodynamics. First, the mathematical model of the WEC was developed and verified through the comparison of float response amplitude between the time domain and frequency domain. Subsequently, key bistable parameters were selected to conduct parametric and modal analysis on the heave response, oscillation states, and power capture efficiency of the WEC based on coaxial double cylinders, with respect to the float principal dimensions. The influence mechanism of the bistable mechanism on power capture was also investigated. Increasing the outer radius of the torus, reducing its draft, and enlarging the spar radius were found to enhance the power capture efficiency and to broaden energy capture bandwidth. The inter-well response of the bistable mechanism reduces the natural frequency of the torus and brings it closer to the wave frequency, resulting in the overall bistability of the WEC and improved power capture efficiency. Finally, the power capture performance of the WEC with an actual float configuration (PowerBuoy and WaveBob type WECs) were studied, analyzing the influence patterns of float hydrodynamic coefficients on power capture efficiency. Compared to the PowerBuoy type WEC, the WaveBob type WEC exhibits greater hydrostatic stiffness for its spar, leading to a significant improvement in power capture efficiency under the effect of different bistable stiffness.