叶片停机位置对风力机塔架绕流及尾流特性影响

Impact of blade stopped positions on the flow around wind turbine tower and its wake performance

上风型风力机叶片的绕流和旋转直接影响塔架周围的流场,以南京航空航天大学自主研发的3 MW水平轴风力机塔架-叶片体系为研究对象,采用大涡模拟(LES)方法对叶片不同停机位置(共计八种计算工况)下风力机塔架绕流和尾流特性进行了数值模拟,并与国内外脉动风压实测曲线进行对比验证了LES方法的有效性。在此基础上,对比分析了叶片不同停机位置对风力机塔架表面压力系数、整体升力及阻力系数、绕流和尾流特性的影响;研究表明叶片停机位置对塔架绕流及气动力分布的影响显著,其中工况五的停机位置最为不利,工况一的停机位置最为有利。主要研究结论可为大型风力机在停机状态下的抗风设计提供参考依据。

The flow around blades and the rotating of blades have a direct impact on the flow filed around the tower of upwind wind turbines. The 3 MW wind turbine developed by Nanjing University of Aeronautics and Astronautics was taken as a study object. The influences of blades positions on the flow around the wind turbine tower and its wake characteristics in stopped state were simulated by using the method of large eddy simulation（ LES）. In order to verify the effectiveness of the LES method,the results were compared with fluctuating wind pressure curves in domestic and foreign literatures. The influences of blades positions on the blade surface pressure coefficient,integral lift and drag coefficient,flow around the tower and wake characteristics of the tower were analyzed. The results show that blades positions have a great effect on the flow around the tower. According to the distribution of aerodynamic force,the condition five is the most unfavorable and the condition one is the most benificial. The main conclusions could be referential to determine the wind load in stopped state in the large wind turbine design.