Experimental Studies on the Drag Reduction and Lift Enhancement of a Delta Wing

Abstract

An experimental wind-tunnel investigation is undertaken to determine the effects of riblets and Gurney e aps on a 40-deg delta wing at a chord Reynolds number of 2 :5£ £10 5 . The results show that riblets reduce the drag of the delta wing over a range of angle of attack; the V-shaped riblet with h=s=0.2 mm has the most signie cant effect at an angle of attack of 6 deg. A drag reduction of 40% is obtained, and the corresponding lift-to-drag ratio is also a maximum with an increase of about 61% over the clean wing. On the other hand, in comparison with the baseline clean cone guration, all Gurney e aps increase the lift coefe cient. The best performance is obtained for the 1% chord Gurney e ap, which yields a maximum lift-to-drag ratio at a 6-deg angle of attack; this provides an increase of 17.3% compared with the clean wing cone guration. However, no favorable effects are found when the riblets and the Gurney e aps are used together.