Keywords

wing design optimization, tailless aircraft design, winglets, tip extensions, C-wings, active load alleviation

Abstract

Conceptual wing design analysis methods are combined with numerical optimization to find minimum drag wings subject to constraints on lift, weight, pitching moment, and stall speed. Tip extensions and winglets designed for minimum drag achieve similar performance, with the optimal solution depending on the ratio of the maneuver lift coecient to the cruise lift coecient. The results highlight the importance of accounting for the depth of the wing structural box in the weight model, and including constraints on stall speed. For tailless aircraft, C-wings show a slight performance advantage over wings with winglets when longitudinal trim and stability constraints are considered. This performance advantage is more significant for span-constrained or low sweep designs. Finally, to demonstrate other possible applications of the method, planar wings with active load alleviation are optimized, showing drag savings on the order of 15%.

Original Publication Citation

Ning, A., and Kroo, I., “Multidisciplinary Considerations in the Design of Wings and Wing Tip Devices,” Journal of Aircraft, Vol. 47, No. 2, Mar. 2010, pp. 534–543. DOI: 10.2514/1.41833