Starting performance effect of a truncated-cone-shaped wind gathering device on small-scale straight-bladed vertical axis wind turbine

Abstract In order to improve the starting performance of straight-bladed vertical axis wind turbine (SB-VAWT), an innovative truncated-cone-shaped wind gathering device (WGD) which could be installed up and down of the rotor was proposed to collect more incoming flow and increase wind speed. The main object of this study is to research the starting performance effects of the main structural parameters of the WGD on small-scale SB-VAWT. The studied parameters of the WGD included the cone angle, height and the distance to rotor. Based on the method of quadratic rotary orthogonal combination design, starting torque performance effects of the three parameters of WGD on SB-VAWT were researched by numerical simulation firstly. Two better structural parameter combinations of WGD were obtained. The static flow fields around the rotor with WGD were calculated. Furthermore, the model of the two kinds of WGD were designed and made. Wind tunnel tests were carried out on the static torque characteristics, rotational speed performance from static condition to stable rotational condition and the power characteristics at different tip speed ratios. According to the results, the new WGD proposed in this study was proved to be effective for both the static and dynamic performance improvement of SB-VAWT. This research can provide a reference for the study of optimum WGD for improving the performance of SB-VAWT.