Wind Tunnel Test for Drag Reduction of Airfoil Bionic Soft Surface

The soft surface of birds and aquatic organisms in the nature can effectively reduce the drag. Inspired by the fact in this paper, an attempt is made to stick silicone rubber soft surface on the surfaces of NACA 4412 and NACA 6409 airfoils. The drags, lifts and lift-drag ratios of airfoils with soft and rigid surfaces in 5 different thickness were compared through wind tunnel test under the condition of = 0 . The results show that most of the bionic soft surfaces play the role of reducing the aerodynamic drag, and also increasing the lift at the same time, in which the soft surface of 0.6mm had the most significant effect of drag reduction and lift increasing. (2014) Trans Tech Publications, Switzerland.