风轮仰角对风力机气动性能的影响研究

EFFECT OF ELEVATION ANGEL OF WIND ROTOR ON AERODYNAMIC CHARACTERISTICS OF WIND TURBINE

为了防止叶片梢部与塔架碰撞,实际工程中的风力机在运行状态下风轮存在一定的仰角,这使得风力机气动荷载状况变得更加复杂。针对此复杂工况,利用计算流体动力学（computational fluid dynamics,CFD）数值模拟方法,对比分析仰角为0°与5°两种风轮模型分别在均匀来流和切变来流条件下的气动荷载特性。结果表明：仰角的存在使得风轮产生与切变风工况方向相反的俯仰力矩和较大的偏航力矩,但对输出功率的影响较小。同时风轮仰角会改变单个叶片气动荷载的波动特性,导致作用于风轮总体的周期性波动荷载增大,其中偏航力矩的波动均方根增大幅度达到了25.46%,将对结构的疲劳性能产生较为显著的影响。

In order to prevent usually has an elevation angle, Wang Haijun Safety, Tianjin University, Tianjin 300072, China） the collision between the blade tip and the tower in operating condition, the wind rotor which will make the aerodynamic loads of wind turbines more complicated. Aiming at the complex condition, comparative analysis of the aerodynamic load characteristics of two kinds of wind rotor models with 0~ elevation angle and 5~ elevation angle have been studied using computational fluid dynamics numerical simulation method under the condition of uniform inflow and shear inflow. The results show that the existence of elevation angle can make the wind rotor produce a larger yawing moment and a pitching moment in the opposite direction with wind shear, but the influence on the output power is a little. Meanwhile, the elevation angle of wind rotor can also change the wave characteristics of aerodynamic loads for the single blade, causing the cyclical fluctuations loads on overall wind rotor to increase, in which the fluctuation root mean square amplitude of yawing moment increases by 25.46% and it will have a noticeable impact on the fatigue performance of the structure.