风雨作用下风力机流场及气动性能分析

FLOW FIELDS AND AERODYNAMIC PERFORMANCE ANALYSIS OF WIND TURBINE UNDER WIND AND RAIN INTERACTION

风雨作用下雨滴会改变风力机流场及叶片气动力,影响风力机的安全和稳定运行。以某1.5 MW风力机为研究对象,基于多参考坐标系法和欧拉两相流法,得到风雨作用下风力机流场和雨滴收集率分布;在此基础上,结合欧拉壁面液膜模型对雨滴在叶片表面的累积过程进行计算,分析叶片气动性能。计算表明:风雨作用下叶片表面雨滴收集率沿展向逐渐增大;雨滴首先在压力面上形成雨膜,并逐步扩展到吸力面中部和叶尖区域,而叶根附近较难形成雨膜;雨滴引起的叶片表面压力的改变主要在压力面上,压力增加值与风压比值最高可达12.5%。计算结果能够为风力机的抗风雨设计及风雨条件下风力机的安全运行提供参考。

Raindrops under interaction of wind and rain will change the flow field of air and aerodynamic load of blade,and affect the safety and stability of wind turbine.A 1.5 MW wind turbine is taken as an example,the flow field and raindrop collection efficiency under the interaction of wind and rain are computed based on the Multiple Reference Frame(MRF)and Eulerian Two-Phase theory;and then the accumulation process of raindrops on the surface of blade and the aerodynamic performance of blade are obtained based on Euler wall film model.The results show that the raindrop collection efficiency on the blade surface increases along the blade span under the interaction of wind and rain;raindrops form film on the pressure side firstly,and then expand to the middle area of suction side and the tip area,but it is difficulty to form film near the root area of blade.The change of the surface pressure on blade caused by raindrops is mainly on pressure side,and the ratio of the wind pressure increase value to the wind pressure reaches up to 12.5%.The derived results are helpful to develop more reliable design for wind and rain resistance of the wind turbine,and the safe operation of the wind turbine under wind and rain interaction conditions.