Numerical simulation of ice accretion and effects of the ice on the wind turbine blade airfoil aerodynamic characteristics are studied. Reynolds average Navier-Stokes equations are solved to obtain the flow field around the airfoil with k-ω SST turbulence models being used. Droplet trajectories are acquired using Lagrangian method, based on which the local collection efficiency can be obtained with multi-dispersed droplet distribution being considered. According to conservation of mass and energy, ice accretion rate and ice shape are calculated on the premise that heat flow around the airfoil surface is obtained. At the same time, effects of time on ice accretion are taken into account, and the numerical simulation of ice accretion is accomplished using multi time-step method. Ice shapes on the airfoil and the flow field around iced airfoil in various ambient and meteorological conditions are simulated. Comparison of the aerodynamic characteristics is made between the clean and the iced airfoils, illustrating that glaze ice would deteriorate the wind turbine aerodynamic performance more than rime ice which is formed when the temperature is relatively higher. Ice on the airfoil leads to lower lift and higher drag causing lower lift-drag ratio by the maximum of 61 %. Also , the iced airfoil may stall at a lower angle of attack, which results in a degradation of the wind turbine performance.%研究了风力机叶片翼型的结冰数值模拟方法,及翼型结冰后对其气动性能的影响.求解雷诺平均N-S方程,引入k-ω SST湍流模型封闭方程,获得风力机叶片流场；采用拉格朗日法计算风力机叶片翼型周围的水滴运动轨迹,同时考虑了多尺寸水滴分布的影响,获得翼型表面的局部水收集系数分布；根据质量守恒和能量守恒原理,计算翼型表面的各项热流,获得翼型表面的结冰速率和结冰冰形；考虑到翼型结冰是时间的动态函数,采用多时间步长法完成结冰数值模拟.计算了风力机叶片翼型在不同环境条件和气象条件下的结冰冰形,同时模拟了风力机翼型结冰后周围流场的变化,并与干净翼型的气动特性进行了对比.结果表明,环境温度较高时形成的明冰对翼型气动性能的影响较大,结冰导致翼型升力下降,升阻比减小,最大减小幅度达到61％,同时结冰后的翼型会提前进入失速区,导致桨叶气动性能恶化.
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