Computational fluid dynamics and experimental study of a model-scale two-body hinged raft wave energy converter

The two-body hinged raft wave energy converters (WECs) have a significant potential to harvest ocean wave energy for electricity generation. Optimization of these devices is crucial for efficient energy conversion, and computational fluid dynamics (CFD) simulation can serve as a pivotal tool to achieve this goal. CFD is capable of unveiling the underlying physics since it can simulate nonlinear waves and nonlinear wave-structure interaction. This paper presents the validation of a CFD model for a 1:20 model-scale WEC from Crestwing and solutions to address some of the challenges in CFD-based WEC simulations. For instance, the calibration of a simplified damper model to approximate the highly nonlinear power take-off (PTO) system, and the simulation of complex motion using overset mesh technique with adaptive mesh refinement (AMR). The numerical results correspond appropriately with the model test results ($8.4 \, \%$ difference in terms of absorbed power). Furthermore, this paper elucidates key characteristics of the Crestwing WEC through flow visualizations, and a sensitivity study of mass, position of the center of mass and width of the device. Latter aims to explore the potential for optimizing the wave energy converter towards higher capture width ratio (CWR) and lower levelized cost of energy (LCOE).