5MW大型风力机气动特性计算及分析

Simulation and Analysis of the Aerodynamic Characteristics of a 5MW Wind Turbine

分别采用BEM和CFD方法对NREL 5 MW风力机的气动特性进行计算,通过分析不同风速下各气动参数的变化规律,揭示了大型变速变桨风力机的功率特性和载荷特性。两种计算结果的详细对比和分析表明,高风速时由于雷诺数大幅增加,BEM方法计算的功率和载荷偏大,在采用BEM方法进行大型风力机的气动设计和校核时,应当考虑雷诺数的影响。同时,失速延迟修正和叶尖损失修正模型在高风速时有较大误差,有必要深入验证传统的修正模型在大型风力机上的适用性。

The aerodynamic characteristics of NREL 5 MW wind turbine were calculated via BEM and CFD methods,respectively.Through the analysis of aerodynamic parameters at different wind speeds,the power and load characteristics of large variable speed and pitch-regulated wind turbines were revealed.A close examination of the results of two methods shows that,the BEM method will obtain relative too large results at high wind speeds,because of the substantial increase of the Reynolds number.In the design and verification process of large wind turbines with the BEM method,the Reynolds number effect should be taken into consideration.Meanwhile,the stall delay and the blade tip loss correction model have a relative larger error at high wind speeds,which should be verified in depth.