Analytic Drag Prediction for Cambered Wings with Partial Leading-Edge Suction

Rapid estimation of a wing's drag polar accounting for the combined effects of planform and profile drag represents a significant challenge, but is of necessity for preliminary analysis and design. In this paper, methodology is presented culminating in simple expressions allowing the combination of these drag components. Information required is knowledge of the wing's sectional characteristics as well as the planform's lift-curve slope and inviscid span efficiency factor. Airfoil profile drag is interpreted as a loss of leading-edge suction. Effects of camber are explicitly accounted for. The method also lends itself to be used as a design tool in which camber and suction may be optimized to minimize drag, depending on the operating conditions. Comparisons of the method with the experimental data show encouraging agreement.