A numerical study on choosing the best con fi guration of the blade for vertical axis wind turbines

Detailed studies on wind turbines have been attracting increasing attention in recent years in order to save fossil resources and protect the environment. Vertical axis wind turbines (VAWTs) are not as popular as horizontal axis wind turbines (HAWTs) because of their relatively low efficiency. Based on CFD approaches, this paper studies the influence of the aerofoil's maximum camber as well as its position along the chord on the performance of the VAWT. During this process, a Kriging model is established to reflect the functional relationship between the design variables and the power coefficient of the VAWT and the numerical samples of the blade configuration for this model are accessed by the Latin Hypercube Sampling approach. The influence of the aerofoil's thickness is studied based on the two-dimensional symmetrical NACA 4 digits aerofoils. In addition, based on a three-dimensional numerical model, this paper investigates the influence of the blade's configuration along the span-wise direction on the blade's power coefficient and the flow characteristics around it. The current results show that the straight blade with a symmetrical aerofoil has the best power efficiency. Also, the thickness of the NACA0018 aerofoil is the most suitable for the operating conditions investigated.