雷诺数对气动弹片改善失速特性影响的数值研究

Effects of Reynolds Number on Stall Characteristics of an Airfoil with Flaps

以NREL S809为原始翼型,采用数值模拟方法得到不同雷诺数下各弹片角度对翼型气动性能的影响,并利用功率谱分析非定常流场气动参数的波动情况。结果表明:在不同雷诺数下,改善翼型气动性能的最佳弹片角度与攻角均近似呈线性关系;与低雷诺数相比,高雷诺数下流体对翼型表面有更强的贴附能力,使得对应攻角下最佳弹片的角度更小;高雷诺数时,在各攻角下弹片改善翼型气动参数波动的能力均较强,而低雷诺数时其能力明显减弱。

Taking the airfoil NREL $809 as an object of study, numerical simulations were conducted to investigate the effects of flap angles on the aerodynamic performance of the airfoil at different Reynolds num- bers, while the aerodynamic parameters of unsteady flow field were analyzed with power spectrum. Results show that the optimal flap angles are approximately linear with respect to the angles of attack at different Reynolds numbers. The fluid has stronger attaching ability to the airfoil surface at higher Reynolds numbers, making the optimal flap angles get smaller at corresponding angles of attack. The flap at high Reynolds numbers has stronger ability to reduce the fluctuation amplitude of aerodynamic parameters than that at low Reynolds numbers.