水平轴风力机叶片非定常气动特性分析

Unsteady aerodynamic characteristic analysis of horizontal axis wind turbine blade

针对水平轴风力机叶片的非定常气动特性,采用状态空间描述的、改进的B-L动态失速模型进行风力机翼型非定常气动力分析.模型采用不可压缩假设并忽略了前缘流动分离所产生的非定常效应,考虑气流的近尾流效应和在失速区域的后缘分离效应以揭示翼型在任意运动中的非定常气动力.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2个用于描述近尾流效应中的时间迟滞,另2个用于描述后缘分离效应,得到了风力机翼型非定常气动升力、阻力和力矩状态变量表达式及计算流程.通过对NACA0012风力机翼型的非定常气动力分析表明,模型能较好地描述风力机翼型的动态特性.

For the unsteady aerodynamic characteristics of horizontal axis wind turbine blade,an unsteady aerodynamic force analysis for wind turbine airfoil was performed based on the improved Beddoes-Leishman dynamic stall model in a state-space formulation.The incompressible assumption was adopted and the unsteady effect from the leading edge flow separation was neglected in the model.The near wake effect and the trailing edge separation effects in stall region were considered to reveal the unsteady aerodynamic forces on an airfoil undergoing arbitrary motion.Four aerodynamic states were adopted to describe the dynamics of unsteady aerodynamic force coefficients,where two states were applied to model the time-lag in the near wake effect and the other two states were used to describe the trailing edge separation effect.The state variable formulations of the unsteady aerodynamic lift,drag and pitch moment on the wind turbine airfoil and the corresponding calculation process were obtained.The analysis for the unsteady aerodynamic forces of a NACA 0012 wind turbine airfoil shows that the present model can preferably describe the unsteady aerodynamic characteristics of wind turbine airfoils.