Numerical investigation of different morph wing configurations for the rolling maneuver

Wing design in the last decades directed efforts and studies to improve the aircraft performance allowing fuel reduction, which implies more ecological and sustainable solutions and cost reduction for air transportation. Efficient design with a morph wing can fulfill such objectives. Different concepts of morph wing have been numerically investigated in this study proposing different wing configurations with the aim to improve aircraft performance in particular for the rolling maneuver. The assessment is performed by using an aerodynamic analysis based on a low fidelity 2D method such as the panel method, in combination with a 3D analysis using vortex lattice method, without considering elastic structural effects. The main morph wing concept is based on the constant morph of a part of the wing tip which has the aim of acting as a control surface hence as a substitution of the aileron for the rolling maneuver. The twist will then be applied linearly decreasing to the center of the wing. Within this concept three main configurations were evaluated: (a) the twist of the fixed airfoil section (Morph type M1 – rib twist), (b) the twist of the aileron which profile is changing according to a curvilinear law based on two morph angles (Morph type M2) and (c) both trailing edge and leading edge are morphed (Morph type M3). A comparison with a correspondent conventional aileron configuration at the same rolling moment coefficient showed an advantage of the morph wing in terms of drag coefficient with reductions that go up to 30%. It was also observed that in some cases such as M1 and M2C a morph deflection lower than 10° produce the same rolling moment coefficient of a typical small aircraft aileron deflection of 25°. Moreover, a parametric evaluation showed an optimum of the span wise parameter yrib to be 40% of the semi span b. Furthermore, a smoother distribution of the lift along the span wise direction will be determined in comparison with a conventional aileron. This also implies a smoother approach to stall conditions that can be beneficial for the pilot.