考虑偏航效应大型风力机风-雨致结构响应与稳定性能研究

RESEARCH FOR STRUCTURAL RESPONSES AND STABILITY CAUSED BY WIND-RAIN LOADS FOR LARGE WIND TURBINE CONSIDERING YAW EFFECT

以南京航空航天大学自主研发的5 MW水平轴风力机为研究对象,首先基于CFD技术模拟了不同偏航角(0°、5°、10°、20°、30°和45°)下风力机体系周边风场,验证风场有效性后添加离散相模型(DPM)并进行风-雨双向耦合迭代计算,然后对比研究不同偏航角对塔架和叶片表面风驱雨量、雨滴附加作用力以及等效压力系数等的影响规律。在此基础上,结合有限元方法重点对风作用和风雨共同作用下不同偏航角工况的大型风力机体系结构响应、屈曲稳定以及极限承载能力等进行定性和定量的对比分析。研究表明:偏航角的改变会显著影响风力机体系的流场特性与受力性能,风-雨荷载共同作用增大了体系结构位移以及内力响应,同时降低了风力机整体屈曲稳定和极限承载能力。上述结论可为此类风力机在极端气候和复杂工况下的荷载预测提供参考。

Taking a 5 MW horizontal wind turbine developed independently by Nanjing University of Aeronautics and Astronautics as an example,the flow field of wind turbine considering different yaw angles(0°,5°,10°,20°,30° and45°)was simulated based on the computational fluid dynamics(CFD)method firstly. And the discrete phase model(DPM)was added and the iterative computations of rain and wind loads were carried out after the effectiveness of the numerical simulation being verified. And then the influence sales of different yaw angles on wind-driven rainfall,raindrop additional force and equivalent pressure coefficient on tower and blades were studied. On the basis of this,the structural responses,the buckling stability and the ultimate bearing capacity of large wind turbine were carried out the qualitative and quantitative analysis for different yaw angles by the finite element method under wind load action and simultaneous actions of wind and rain loads. Studies show that the flow field characteristics and mechanical properties caused by wind and rain loads of wind turbine are significantly affected with the change of yaw angles. The displacement and internal force responses of wind turbine system are increased under simultaneous action of wind and rain loads. And then the buckling stability and ultimate bearing capacity of wind turbine are reduced under simultaneous action of wind and rainloads. The conclusions can provide references for load forecast of such wind turbines under extreme climates and complex conditions.