Investigation of the combined influence of arrangement and configuration parameters on the performance of vertical axis wind turbines in staggered arrangements

Abstract

Vertical-axis wind turbine (VAWT) array has attracted much attention due to its higher power density, but existing studies put little emphasis on the configuration parameters of one VAWT in array. Thus, a comprehensive study was carried for the combination effect of arrangement and configuration parameters on the aerodynamic performance of two VAWTs in staggered arrangements. Mutual influence of two turbines under different relative arrangement angles (θ), turbine spacing, blade pitch angles (BPA), and tip speed ratios of the downstream turbine were investigated. A major finding is that the location of the downstream VAWT can be divided into two regions with θ = 60° as the turning point, where the regular patterns of the average power coefficient of double VAWTs (CP,avg) with BPA are different. When the downstream turbine is located in the high-speed zone (θ ≤ 60°), positive BPAs benefit the performance of turbines, and 2.5° is the general optimal BPA. While for the case of downstream VAWT in the wake region (θ > 60°), the optimal BPA is a variable related to turbine spacing. Compared with the zero pitch blade, the maximum CP,avg can increase by 7.3% at most (in the 2D-75° case). Flow characteristic analysis indicated that the trigger of the dynamic stall and the wake interaction is the main reasons for different operation features of staggered arrangements.