In recent decades, the emphasis on renewable resources has grown considerably, leading to significant advances in the sector of wave energy. Nevertheless, the market cannot still be considered as commercialized, as there are still other obstacles in the mooring system for wave energy converters (WECs). The mooring system must be designed to not negatively impact the WEC’s efficiency and reduce the mooring loads. Firstly, the overview of the types of wave energy converters (WECs) are classified through operational principle, absorbing wave direction, location, and power take-off, respectively, and the power production analysis and design challenges of WECs are summarized. Then, the mooring materials, configurations, requirements, and the modeling approaches for WECs are introduced. Finally, the design of mooring systems, including the design considerations and standards, analysis models, software, current research focus, and challenges are discussed.

The growing interest in renewable energy solutions for sustainable development has significantly advanced the design and analysis of floating offshore wind turbines (FOWTs). Modeling FOWTs presents challenges due to the considerable coupling between the turbine’s aerodynamics and the floating platform’s hydrodynamics. This review paper highlights the critical role of computational fluid dynamics (CFD) in enhancing the design and performance evaluation of FOWTs. It thoroughly evaluates various CFD approaches, including uncoupled, partially coupled, and fully coupled models, to address the intricate interactions between aerodynamics, hydrodynamics, and structural dynamics within FOWTs. Additionally, this paper reviews a range of software tools for FOWT numerical analysis. The research emphasizes the need to focus on the coupled aero-hydro-elastic models of FOWTs, especially in response to expanding rotor diameters. Further research should focus on developing nonlinear eddy viscosity models, refining grid techniques, and enhancing simulations for realistic sea states and wake interactions in floating wind farms. The research aims to familiarize new researchers with essential aspects of CFD simulations for FOWTs and to provide recommendations for addressing challenges.

This study presents a detailed numerical investigation of a floating offshore wind turbine (FOWT) subjected to focused wave excitation, utilizing a high-fidelity, fully coupled aero-hydro-mooring computational fluid dynamics model implemented in OpenFOAM. The analysis focuses on the National Renewable Energy Laboratory 5-MW reference turbine mounted on a semi-submersible platform. The influence of wave focus positions, located upstream (FP-US), at the mid-position (FP-M), and downstream (FP-DS), is systematically evaluated in terms of platform motions, mooring line tensions, aerodynamic loading, and wake recovery behavior. Time–frequency spectrograms are employed to characterize the non-stationary and transient responses induced by the focused wave conditions. The results indicate that pitch motions are significantly amplified in the FP-US and FP-M cases compared to FP-DS, with strong pitch and surge coupling observed. Surge motions are also more pronounced in FP-US and FP-M, where low-frequency components corresponding to the natural surge frequency contribute to prolonged dynamic responses. Mooring line tensions follow a similar trend, with substantially higher loads in FP-US and FP-M due to intensified wave-induced excitation. Additionally, FP-US and FP-M demonstrate improved aerodynamic performance and wake recovery, although accompanied by increased aerodynamic fluctuations resulting from platform motions. These findings indicate the importance of accounting for wave focus positions to improve the FOWT design and performance, especially for long-term stability and efficiency.