To analyze the effect of Gumey flap on the aerodynamics performance of airfoil ,CFD commercial software Fluent are selected to simulate NACA44I2 airfoil with and without Gumey flap. First, the boundary conditions and turbulence model are ascertained through the comparison of several computation results with experiment results; then the effect of Gurney flap on the flow field and lift enhancement are analyzed though comparison of pressure distribution of clean airfoil and airfoil with 1% 、2% 、4% chord height Gumey flap. The results show that between 5~ + 17 attack angle the lift force can be enhanced effectively ,and the larger the gumey flap height is,the higher the lift is. At the same time the drag force can be raised. Affected by lift and drag force the lift drag ratio change litlle at little attack angle and increase at middle and large attack angle. The low pressure zone induced by Karman vortex and the high pressure zone induced by comer vortex are the main reason for lift enhancement.%为了分析襟翼对风力机翼型气动性能的影响,采用 FLUENT软件对带有襟翼和不带襟翼的NACA4412翼型进行了数值模拟.首先通过不同计算模型结果与实验数值的对比,确定了适用于翼型计算的数值边界条件和湍流模型；其次,通过比较无襟翼和1％、2％、4％弦长 3种襟翼高度的翼型气动性能和流场的压力分布等,对襟翼对流场的影响和增升原理进行了分析.结果表明:在-5°～+17°攻角范围内,Gurney均可有效增加翼型升力,并且襟翼高度越大增升越明显,但同时阻力也会有所增加,受二者共同作用在小攻角时升阻比变化不大,大攻角时升阻比明显增加.襟翼后卡门涡街代表的低压区和襟翼前角涡代表的高压区的形成是增加翼型升力的根本原因.
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