In recent years, the construction of offshore wind farms is developing rapidly. As the wake effect of the upstream wind turbines seriously affect the performance of the downstream wind turbines, the wake effect of offshore wind turbines has become one of the research hotspots. First, this article reviews the research methods of wake effects, including CFD numerical simulation method, wind turbine wake model based on roughness and engineering wake models. However, there is no general model that can be used directly. Then it puts forward some factors that affect the wake of offshore wind turbines. The turbulence intensity in offshore wind fields is lower than that in onshore wind fields. This makes the wake recovery length of offshore wind turbines longer than that of onshore wind turbines. Floating offshore wind turbines are simultaneously disturbed by wind loads and wave loads. Unsteady movement of the platform caused by wave loads. It affects the development and changes of the wake of wind turbines. In this regard, the focus of research on the wake effects of offshore wind farms will be the proposal of accurate prediction models for the wake effects of sea wind farms.

In the complex and harsh working environment of wind turbines, the horizontal axis wind turbine blade is increasingly confronted with the issue of surface roughening. It leads to a decrease and instability in the output power of the horizontal axis wind turbine. Vortex generator have emerged as a potential solution to this problem by regulating the flow patterns on the blade surface. This research focuses on exploring the impact of vortex generator on the aerodynamic performance of blades under rough wall condition by wind tunnel experiment and computational fluid dynamics simulation. It is important to improve the aerodynamic performance of horizontal axis wind turbine under rough condition. The results show that vortex generator changes the airfoil aerodynamic performance by slowing the stall angle of attack and increasing the ratio of lift-drag in some angles of attack. vortex generator delays the flow separation of the suction surface under the rough wall condition. It is able to counteract the reduction in the aerodynamic performance of blade under rough wall condition. At tip speed ratio is 5.83, vortex generator increased power coefficient by 47.8% under rough wall condition by reducing the flow separation area of 33% radius and weakening the spanwise flow. The study found that the vortex generator effectively eliminated the negative effects of blade surface roughening on aerodynamic performance, improved the roughness insensitivity of the blade, and has good potential for future applications.