FSI simulations and analyses of a non-resonant buoyant wave energy converter

Deploying wave energy converters (WECs) in wave parks into the ocean requires detailed planning and numerical analyses to maximize the wave energy capture and keep the LCoE at the lowest possible level. High-fidelity simulation models can accurately simulate the fluid-structure interaction (FSI) between the WECs and the ocean’s waves. However, the computation cost is too high for simulations and analyses of large-scale WEC parks. This study presents fully coupled hydrodynamic-structure response simulations and analyses using the high-fidelity CFD software STAR-CCM+, which is compared with the DNV software package SESAM that adopts potential flow theory to model environmental loads. A novel non-resonant heave-point buoyant WEC called NoviOcean is investigated. The first case study, where only one WEC was modelled, showed that both simulation approaches/software gave comparable WEC motion results for moderate sea state conditions, but the SESAM software required significantly less computation cost. Hence, the SESAM model was used in systematic simulations of two WECs to investigate the effect of FSI on the energy capture by both WECs by varying the distance between the WECs and the wave direction. The results show which WEC distances and wave directions should be preferred to maximize the wave energy capture