This paper presents the results of ongoing work regarding numerical simulations of breaking wave impacts on a surface-piercing cylinder. The computational fluid dynamics solver, Code_Saturne, using the volume of fluid approach, is presented and utilised for offshore hydrodynamics. Phase-focused waves are employed to recreate singular breaking events under relatively controlled conditions. The fluid shape and kinematics are described during the breaking process and the load produced by a plunging breaker on a rigid cylinder is investigated.
Bottom fixed and floating offshore wind turbines are growing in popularity and developing towards being an economically viable alternative to conventional carbon-based energy forms. During the past few decades, most offshore wind turbines were installed on monopile foundations relatively close to the coastline. More recently, the energy sector is gradually embracing the possibility of expanding towards deeper waters, mostly motivated by the presence of stronger and more stable winds, and the availability of a wider range of areas. The water depths on these locations make the installation of conventional bottom fixed structures difficult, and newer approaches using floating turbines are more viable solutions.
The rapid growth of this sector and the large number of turbines to be installed in a single park requires different approaches for their design, manufacturing, and installation, compared to the typical procedure for existing offshore structures, e.g., oil and gas. These new approaches provide an opportunity for optimization and standardization, however, and old design challenges, which may carry general uncertainties, need to be revisited and properly addressed.
The targeted locations for offshore wind turbines are often affected by the presence of energetic steep or breaking waves (ESBWs) and these may be an important contributor to the overall loading of the structure affecting the Ultimate Limit State. Unlike nonbreaking focused waves (e.g., Sriram et al., 2020), when ESBWs interact with the structures, they lead to violent motions of the liquid and a significant transfer of momentum occurs in very localised spatial and temporal scales. These so-called slamming events, are likely to occur during storm conditions and the related resultant forces are poorly predicted if using the classic Morison's formula (Morison et al., 1950). The applicability of such an approach in complex situations has been studied by Saincher et al. (2022).
