论文部分内容阅读
为研究仿生波状前缘对翼型失速性能的影响,本文采用S-A湍流模型,对风力机翼型NACA634-021(光滑前缘)以及对应的正弦波状前缘仿生翼型的绕流流场进行了数值模拟。结果表明,光滑翼型在20°攻角附近发生深度失速,升力系数骤然下降;而波状前缘仿生翼型有效改善了失速特性,升力系数变化较平稳,在大攻角下高于光滑翼型。通过流场分析发现光滑翼型失速前后升力系数骤然下降的主要原因在于前缘压力面和吸力面的压差大幅度下降,而仿生翼型改变了前缘的压力分布特性,进而改变了大攻角下的分离特性,促进流向涡对的产生和发展,使得凸峰附近保持附着流动,进而提高升力。
In order to study the influence of the bionic wavy leading edge on the aerofoil stalling performance, a SA turbulence model was used to simulate the flow field around the NACA634-021 (smooth front) and the corresponding sine-wave bionic airfoil Numerical Simulation. The results show that the smoothing airfoil has a deep stall near the angle of attack of 20 °, and the lift coefficient suddenly drops. The wavy front edge bionic airfoil effectively improves the stalling characteristics, the lift coefficient changes more smoothly, and is higher at the angle of attack than the smooth airfoil . The main reason for the sudden drop of the lift coefficient before and after the smooth airfoil stall is that the pressure drop between the leading pressure surface and the suction surface decreases sharply, while the bionic airfoil changes the pressure distribution characteristics of the leading edge, which in turn changes the big attack Angle of the separation characteristics, and promote the flow of vortex generation and development, making the convex peak near the attachment flow, thereby enhancing the lift.