In recent years, leading-edge tubercles have gained significant attention as an innovative biomimetic flow control technique. This paper explores their impact on the aerodynamic performance and flow patterns of an airfoil through wind tunnel experiments, utilizing force measurements and tuft visualization at Reynolds numbers between 2.7 × 10⁵ and 6.3 × 10⁵. The baseline airfoil exhibits a hysteresis loop near the stall angle, with sharp changes in lift coefficient during variations in the angle of attack (AOA). In contrast, the airfoil with leading-edge tubercles demonstrates a smoother stall process and enhanced post-stall performance, though its pre-stall performance is slightly reduced. The study identifies four distinct flow regimes on the modified airfoil, corresponding to different segments of the lift coefficient curve. As the AOA increases, the flow transitions through stages of full attachment, trailing-edge separation, and local leading-edge separation across some or all valley sections. Additionally, the study suggests that normalizing aerodynamic performance based on the valley section chord length is more effective, supporting the idea that leading-edge tubercles function like a series of delta wings in front of a straight-leading-edge wing. These insights provide valuable guidance for the design of blades with leading-edge tubercles in applications such as wind and tidal turbines.

The efficient, low-cost, and large-scale development and utilization of offshore wind energy resources is an inevitable trend for future growth. With the continuous increase in the scale of wind turbines and their expansion into deep-sea locations, there is an urgent need to develop ultra-long, flexible blades suitable for future high-capacity turbines. Existing reviews in the field of blade design lack a simultaneous focus on the two core elements of blade performance calculation and design methods, as well as a detailed evaluation of specific methods. Therefore, this paper reviews the performance calculation and design methodologies of horizontal-axis wind turbine blades from three aspects: aerodynamic design, structural design, and coupled aero-structural design. A critical introduction to various methods is provided, along with a key viewpoint centered around design philosophy: there is no global optimal solution; instead, the most suitable solution is chosen from the Pareto set according to the design philosophy. This review not only provides a concise and clear overview for researchers new to the field of blade design to quickly acquire key background knowledge but also offers valuable insights for experienced researchers through critical evaluations of various methods and the presentation of core viewpoints. The paper also includes a refined review of extended areas such as aerodynamic add-ons and fatigue characteristics, which broadens the scope of the review to touch on multiple research areas and inspire further research. In future research, it is crucial to identify new key issues and challenges associated with increased blade length and flexibility, address the challenges faced in integrated aero-structural design, and develop platforms and tools that support multi-objective optimization design of blades, ensuring the safe, stable, and orderly development of wind turbines.

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.