NACA0018翼型锯齿襟翼气动性能的数值研究

Numerical Investigation on Aerodynamic Performance of NACA0018 Airfoil Serrated Gurney Flap

摘要: 以NACA0018翼型作为基础翼型，选取θ = 30˚, 60˚, 90˚三种不同锯齿角度以及d/h = 0.6, 0.8, 1三种不同深度的锯齿襟翼研究锯齿几何参数对翼型气动性能的影响。同时通过改变入口速度研究不同雷诺数下锯齿襟翼对性能的影响。结果表明，锯齿襟翼角度对翼型气动性能影响较小；随着锯齿深度的增加，翼型升阻比降低；随着入口雷诺数的增大，翼型升力逐渐增加，阻力逐渐降低，但增大幅度有所减缓；当格尼襟翼上开锯齿后，原本格尼襟翼后交替脱落的管状涡结构，由于气体从锯齿间隙通过并形成一对流向涡，与格尼襟翼固有的脱落涡掺混耗散，形成破碎的小结构，减弱尾迹流动不稳定性，降低翼型阻力，随着开齿深度的增加，涡核集中区域逐渐向襟翼附近前移，涡的掺混、消散更快。

Abstract: With NACA0018 airfoil as the basic airfoil, three kinds of serrated Gurneyflap with different angles of 30˚, 60˚ and 90˚ and different depths of d/h = 0.6, 0.8 and 1 were selected to study the effects of the serrated geometrical parameters on the aerodynamic performance of the airfoil. At the same time, the performance of the serrated Gurneyflap under different Reynolds numbers was studied by changing the inlet velocity. The results show that the angle of the serrated flaps has little effect on the aerodynamic performance of the airfoil. With the increase of sawtooth depth, the lift-drag ratio of airfoil decreases. With the increase of Reynolds number, the airfoil lift increases gradually and the drag decreases gradually, but the increase rate slows down. When the sawtooth is opened on the Gurney flap, the original tubular vortex structure which falls off alternately after the Gurney flap passes through the serrated gap and forms a convective vortex, which is mixed with the inherent shedding vortex of the Gurney flap to form a broken small structure, which weakens the wake flow instability and reduces the airfoil resistance. The concentration region of vortex core gradually moves forward near the flap, and the mixing and dissipation of vortex are faster.