Offshore wind power has become an important trend in global renewable energy development. Based on a particle swarm optimization (PSO) algorithm and FAST program, a time-domain coupled calculation model for a floating wind turbine is established, and a combined optimization design method for the wind turbine’s blade is developed in this paper. The influence of waves on the power of the floating wind turbine is studied in this paper. The results show that, with the increase of wave height, the power fluctuation of the wind turbine increases and the average power of the wind turbine decreases. With the increase of wave period, the power oscillation amplitude of the wind turbine increases, and the power of the wind turbine at equilibrium position decreases. The optimal design of the offshore floating wind turbine blade under different wind speeds is carried out. The results show that the optimum effect of the blades is more obvious at low and mid-low wind speeds than at rated wind speeds. Considering the actual wind direction distribution in the sea area, the maximum power of the wind turbine can be increased by 3.8% after weighted optimization, and the chord length and the twist angle of the blade are reduced.

The hydrodynamic performance of short-crested wave diffraction by bottom-mounted V-shaped and arc-shaped breakwaters was examined based on the linear wave theory and the eigenfunction expansion method, respectively. Both types of breakwaters are assumed to be thin, impermeable, vertical, and rigidly embedded in the seabed. With the help of a virtual interface, the fluid domains were subdivided into subdomains and the velocity potential in each subdomain was described by eigenfunctions. The linear algebraic equations that determine the unknown coefficients can be obtained using the boundary and matching conditions. The analytical models fully agree with previous predictions. The major factors including wave propagation direction, opening angle, and water depth that affect wave forces and run-ups were explored. The results showed that the wave patterns of short-crested waves near breakwaters were quite different from those of long-crested waves, and using the long-crested wave model can overestimate the wave-defending effects of the breakwaters in a short-crested sea. An analogous wave attenuation effect was observed for breakwaters with comparable structures, which means that engineering practice has a certain degree of substitutability between them.