Abstract: According to the aerodynamic efficiency caused by the strong unsteady and unsteady flow caused by the periodic variations of the blade angle of attack with the phase angle during the operations of the VAWTs, a flow control method for arranging dynamic Gurney flaps at the trailing edges of the blades was proposed. Taking the three-blade linear wing VAWTs as the research object, the numerical simulation method was utilized to study the influences of different movement methods and extension height of Gurney flap on the aerodynamic performance of VAWTs based on SST k-ω turbulence model. The results show that the power coefficient of VAWTs is significantly improved with the addition of dynamic Gurney flaps arranged on the trailing edges of the blades. When the dynamic Gurney flap is constantly maintained at the pressure surfaces, the maximum power coefficient of the whole machine may be increased by 27.9%. Simultaneously, the optimal tip speed ratio is reduced, and the running stability of the wind turbines is improved. Under the low tip speed ratio,the tangential forces of single blade and starting torques of the whole machine are improved with the addition of the Gurney flaps.When the Gurney flap height exceeds a certain range, as the tip speed ratio increases, the power coefficient improvement effectiveness of the whole machine is gradually reduced, meanwhile the blade fatigue load is increased.

Key words: vertical axis wind turbine(VAWT), dynamic Gurney flap, flow control, aerodynamic performance, power coefficient

摘要： 针对垂直轴风力机运行时叶片攻角随相位角呈周期性变化所导致的强非稳定和非定常流动进而引发的气动效率问题，提出在叶片尾缘布置动态格尼襟翼的流动控制方法。以三叶片直线翼垂直轴风力机为研究对象，采用基于SST k-ω湍流模型的数值模拟方法，研究了格尼襟翼不同运动方式及伸出高度对垂直轴风力机气动性能的影响。结果表明：在叶片尾缘布置动态格尼襟翼可有效提高风能利用系数，当动态格尼襟翼始终保持在压力面时，整机最大风能利用率可提高27.9%，同时最佳尖速比降低，风力机运行稳定性提高；在低尖速比下，格尼襟翼能增大单叶片切向力，提高整机在低风速下的启动力矩；当格尼襟翼高度超出一定范围时，随尖速比增大，整机风能利用率提高效果逐渐减弱，同时叶片疲劳载荷增大。

关键词: 垂直轴风力机, 动态格尼襟翼, 流动控制, 气动性能, 风能利用系数