Numerical Simulation of Typhoon Waves in an Offshore Wind Farm Area of the South China Sea

Environmental load data are an essential input for the analysis of offshore wind structures in typhoon-prone marine environments. However, numerical simulations of typhoon waves lack a systematic examination of the specific influence of typhoon trajectories on the spatial evolution of wave fields. In particular, the intricate mechanisms governing wave propagation within wind farm areas remain poorly understood. This present study, drawing upon a real-world case in an offshore wind farm area in the South China Sea, employs the Finite Volume Coastal Ocean Model–Surface Wave Module (FVCOM–SWAVE) wave–current coupling model to assess the joint wind–wave distribution characteristics during 35 typhoon events. The findings reveal that typhoon wave fields exhibit a notable rightward bias. As waves approach the coast, the significant wave height decreases progressively due to wave breaking, friction, refraction, and nonlinear interactions. During the passage of typhoons Prapiroon, Hato, and Mangkhut, the significant wave height distribution in the wind farm area closely correlated with the wind speed distribution. By constructing a joint distribution function of sea wind and wave elements, the joint distribution characteristics of wind speed and significant wave height for different return periods can be obtained, providing important oceanic environmental inputs for the design analysis of offshore wind structures.