风力机翼型非定常气动力分析(英文)

Unsteady Aerodynamic Force Analysis of Wind Turbine Airfoil

基于状态空间描述的Beddoes-Leishman动态失速模型,对风力机翼型进行非定常气动力分析.考虑到风力机翼型工作时的实际情况,在模型中忽略了可压缩性效应和起始于翼型前缘的流动分离.模型考虑了气流的近尾流效应和在失速区域的后缘分离效应.模型用4个气动状态来描述非定常气动力系数动力学,其中两个用于描述近尾流效应中的时间迟滞,另两个用于描述后缘分离效应.采用模型对做简谐变桨运动的FFA-W3-241风力机专用翼型进行了非定常气动力分析.数值计算结果与实验值吻合良好,说明模型能较好地描述风力机翼型的非定常气动特性.将动态失速数值计算模块与已有的风力机气动与结构分析软件集成,利用软件对一台1.5MW变速变桨距风力机的发电工况进行了仿真.仿真结果表明,翼型的非定常气动特性对动态载荷计算结果影响很大,因此在风力机的设计过程中应该予以充分考虑.

An unsteady aerodynamics model based on the Beddoes-Leishman type dynamic stall model in a state-space formulation was presented to predict the unsteady aerodynamic forces on an airfoil undergoing arbitrary motion.According to the operating condition of wind turbine airfoils,the compressibility effects and flow separation initiated from the leading edge were neglected.The model includes the effects of near wake and the effects of trailing edge separation.Four aerodynamic states were adopted to describe the dynamics of the unsteady aerodynamic force coefficients： two states were applied to model the time-lag of the near wake effect,and the other two states were used to model the time-lag effect of trailing edge separation.Applying the proposed model,unsteady aerodynamic forces of a FFA-W3-241 wind turbine airfoil during harmonic pitching motion were calculated.The calculation results showed a good agreement with the experimental data,which indicated that the proposed model ould preferably model the unsteady aerodynamic characteristics of wind turbine airfoils.The numerical dynamic stall module was integrated into a wind turbine aerodynamics and structural dynamics analysis software.Applying the software,a simulation of power production load case of a 1.5MW variable-speed pitch-regulated wind turbine was carried out.The simulation results indicate that unsteady aerodynamic characteristics of airfoils shall be taken into account during wind turbine design process because they significantly affect the transient aerodynamic loads of the rotor.