Aero-Structural Optimization and Performance Evaluation of a Morphing Wing with Variable Span and Camber

Abstract

An aero-structural design and analysis study of a telescopic wing with a conformal camber morphing capability is presented. An aerodynamic analysis of a telescoping wing, first with a high speed airfoil followed by an analysis with a low speed airfoil is performed. The data obtained from these analyses is used to determine the optimum polar curves for drag reduction at different speeds. This information in turn provided the background for devising an optimal morphing strategy for drag reduction assuming that the telescoping wing airfoil has the capability to step morph between the high and low speed airfoils. Next, a conformal camber morphing concept is introduced. The concept is based on a non-uniform thickness distribution along the chord of a wing shell section that deforms from a symmetrical airfoil shape into a cambered airfoil shape under actuation. Structural optimization based on finite element models is used to obtain the shell thickness distribution for minimum shell section weight and best airfoil shape adjustment. Finally, a comparison study between the performance of an aircraft equipped with a morphing wing (telescopic wing combined with conformal camber morphing) and the performance of the same aircraft equipped with an optimized fixed wing for 30 m/s cruise speed and 100 N weight is presented. Aerodynamic optimization based on computational fluid dynamics models is used for the optimum fixed wing geometric parameters calculations. The optimal wing configurations for various performance parameters are calculated. The morphing wing generally outperforms the optimum fixed wing with the exception of a 10% reduction in rate of climb and 4% drag penalty at 30 m/s cruise speed.