翼型加装格尼襟翼的低雷诺数气动特性实验研究

为了研究低雷诺数下格尼襟翼对翼型气动特性的影响,通过风洞试验研究了Eppler387翼型加装0.5%～5.0%弦长高度格尼襟翼后的气动特性变化,试验雷诺数1.49×105～2.31×105。试验结果表明：低雷诺数下Eppler387翼型加装格尼襟翼后,升力系数和力矩系数明显增大,襟翼高度大于2%弦长时阻力系数显著增大。格尼襟翼在高升力系数下能够起到增大升阻比的作用,适用于微小型飞行器工作在大载荷状态,而0.5%弦长高度的襟翼还能够兼顾中小升力系数下的气动效率,同样适合于微小型飞行器在巡航状态使用。与原翼型相比,加装襟翼后最大升阻比对应的迎角提前,随襟翼高度的增加,翼型升阻比曲线峰值变得不再突出。

Experimental study on aerodynamic characteristics of airfoil equipped with Gurney flaps at low Reynolds numbers

In order to study the aerodynamic characteristics of airfoil equipped with Gurney flap at low Reynolds numbers,Eppler387airfoil is equipped with 0.5%～5.0% chord height Gurney flap for wind tunnel test.The Reynolds numbers in the test are from 1.49×105 to 2.31× 105.The results suggest that lift coefficient and moment coefficient of Eppler387airfoil equipped with Gurney flap are improved significantly at low Reynolds numbers.Drag coefficient is also improved when the flap is higher than 2%chord.Lift-to-drag ratio is improved when lift coefficient is high,so that Gurney flaps is suitable for MAV or small aircraft with heavy payload.0.5% chord height Gurney flap is also suitable for cruise,since it has better aerodynamic efficiency at low lift coefficient at the same time.Compared with clean airfoil,the angle corresponding to the highest lift-to-drag ratio becomes smaller with the effect of Gurney flaps.When Gurney flaps are higher,the curves of lift-to-drag ratio become smoother.