Main parameters of the three wind rotors.

Traditional Savonius wind rotor has simple structure and can operate in any wind direction. However, its aerodynamic efficiency is lower than other types. A novel S-shaped wind rotor with three blades is proposed in order to improve the aerodynamic performance. The blade of the rotor is composed of two opposing convex circular arcs and its shape likes an ‘S’. The flow characteristics of the rotor are studied and analyzed by computational fluid dynamics (CFD) numerical simulation method. The steady and transient performances are studied using SST k-ω model and sliding mesh method, and are compared with that of traditional Savonius rotors. The results show that the average static torque coefficient of the rotor is 0.291, which is higher than the 0.222 of the Savonius rotor. The static vibration amplitude of the rotor is 0.375, which is lower than 0.709 of the Savonius rotor. The maximum power coefficient of the rotor is 0.228, which is also higher than the 0.226 of the Savonius rotor. The dynamic vibration amplitude of the novel rotor is 0.183, which is lower than the 0.492 of the Savonius rotor. The flow field analyses show that structure of the S-shaped blades can smooth the flow field and reduce the blocking effect in the overlap area. The study indicates that the proposed navel rotor can not only overcome the problems of sharp change in the internal flow field of traditional Savonius rotors, but also provide better operating stability and higher wind energy utilization.传统萨沃纽斯（Savonius）风力转子结构简洁，可适配任意风向运行，但其气动效率逊于其他类型风力转子。为优化气动性能，本文提出一种新型三叶S形风力转子。该转子的叶片由两组相对布置的凸圆弧构成，整体外形呈“S”形。研究采用计算流体动力学（CFD）数值模拟方法，对该转子的流动特性展开分析与研究；通过SST k-ω湍流模型与滑动网格法，分别探究其稳态与瞬态气动性能，并与传统萨沃纽斯转子的相关性能进行对比。结果显示，该转子的平均静态转矩系数为0.291，高于传统萨沃纽斯转子的0.222；其静态振动幅值为0.375，低于传统萨沃纽斯转子的0.709。该转子的最大功率系数可达0.228，同样优于传统萨沃纽斯转子的0.226；新型转子的动态振动幅值为0.183，低于传统萨沃纽斯转子的0.492。流场分析结果表明，S形叶片结构可优化流场分布，削弱重叠区域的气流阻滞效应。本研究证实，所提出的新型转子不仅能够克服传统萨沃纽斯转子内部流场剧烈变化的缺陷，还可实现更优异的运行稳定性与更高的风能利用率。