Initial lift of finite aspect-ratio wings due to a sudden change of incidence

Abstract

The initial lift for wings of finite aspect ratio due to a sudden unit change of incidence is considered and, by the use of the method developed in R. & M. 21171, the ratio of the initial to the final values of the lift is determined for rectm~gular wings and cropped delta wings of taper ratio 1/7. These values indicate that the initial lift may be greater than the final lift for aspect ratios A =< 2. This result appears to be supported by the values of instantaneous lift which were measured for the delta wing of aspect ratio 1.2 as its incidence was rapidly changed.