To improve the performance of a 3.5 kW small H‐type vertical axis wind turbine (VAWT) with the airfoil of NACA0015, a design method for installing split flaps at the trailing edge of a blade is proposed. By solving the two‐dimensional URANS equations, the simulation of VAWTs is carried out. The influences of the length (10% c‐30% c), arrangement positions (90% c‐70% c), and deflection angles (10°‐30°) of the split flaps on the performance of VAWT are determined by orthogonal design when Reynolds number is 2 × 10⁵ and 1 < TSR < 3. In accordance with the influence degrees of these parameters and adopting the maximum wind energy utilization ratio C_Pmax and the maximum efficient operating range Δλ_max as research objectives, the optimum flap length is determined as 22% c, the optimum deflection angle is 10°, and the optimum arrangement position is 92% c. Further studies show that the C_Pmax is increased by 5.8% and its Δλ_max is increased by 25.9% after installing split flaps. Meanwhile, split flaps can change the Kutta‐Joukowsky trailing edge boundary condition, which increases the flow circulation around the airfoil. Also, split flaps can increase the positive pressure difference in the upwind area and reduce the negative pressure difference in the downwind area, which significantly improves the aerodynamic performance of VAWTs.

中文翻译：

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后缘裂片对垂直轴风力发电机空气动力性能的影响

为了提高带有NACA0015翼型的3.5 kW小型H型垂直轴风力涡轮机（VAWT）的性能，提出了一种在叶片后缘安装剖开襟翼的设计方法。通过求解二维URANS方程，对VAWT进行了仿真。VAWT的性能通过正交确定了襟翼的长度（10％c -30％c），布置位置（90％c- 70％c）和偏转角（10°-30° c）对VAWT性能的影响当雷诺数为2×10 ⁵且1 <TSR <3时进行设计。根据这些参数的影响程度，采用最大风能利用率C _{P max}和最大有效工作范围Δ λ_最大为研究目的，最佳襟翼长度被确定为22％Ç，最佳偏转角为10°，最佳配置位置是92％Ç。进一步的研究表明，C ^ _P最大增加5.8％，并且它的Δ λ_最大安装分体式襟翼后，提升了25.9％。同时，裂开的襟翼可以改变Kutta-Joukowsky的后缘边界条件，从而增加机翼周围的流循环。另外，裂开的襟翼可以增加迎风区域的正压差，并减小顺风区域的负压差，从而显着提高VAWT的空气动力性能。