This paper presents the analysis of an active winglet concept applied to a long-range aircraft. The winglet is actuated along the longitudinal axis to control its cant angle. Due to aeroelastic effects, the wing twist changes and therefore impacts aircraft performance. As a consequence, this technology offers the opportunity to optimize aircraft performance throughout the flight. This ability will be evaluated using high-fidelity coupled aerodynamic and structural computations. The consideration of the wing flexibility and the impact of the winglet on the wing shape contributes to more accurate aerodynamic predictions. First, the winglet geometry is optimized for the cruise condition using surrogate models. The designed winglet reduces the drag with a limited impact on loads while ensuring the capability to change the wing tip twist through the control of the cant angle. Then, a mission analysis is performed to assess the benefits of the technology on a variety of flight conditions.

This paper presents a parametric analysis of an active winglet concept applied to a high aspect ratio wing. The technology studied here only consists in a single degree of freedom wing-tip whose only the cant angle deflection can be controlled. The main parameters under study are the hinge line location and its orientation with respect to the longitudinal axis of the aircraft. High-fidelity aerodynamic and structural computations are used to assess the impact of the device on both drag and loads. The influence of cant angle deflections on flutter characteristics is also evaluated. First a "wing only" configuration is studied and the results are compared with complete aircraft computations to take into account the contributions due to the trim. It is shown that the hinge line parameters highly influence the drag evolution with cant angle but with limited impact on the minimum area -in which we are interested in. Loads are significantly impacted by both cant variations and hinge line geometry. Regarding dynamic characteristics, the mode sequence is dependent on the cant deflection and massively impacts flutter onset.

Increasing the wing aspect ratio appears as a straightforward way to improve aerodynamic performance of transport aircraft by reducing the lift-induced drag component. However, it comes at the price of a direct negative impact on the wing structural weight which is necessary to sustain aerodynamic loads in the case of a conventional cantilever wing. The strut-braced wing concept allows to reduce the flexural moment to be carried out by the inner-wing structure and therefore limits the weight penalty as aspect ratio is increased. A multidisciplinary evaluation of the potential benefits at aircraft level of High Aspect Ratio, Strut Braced Wing concept is presented. It relies on a multi-fidelity design approach in which an Overall Aircraft Conceptual Design framework is combined with high-fidelity aerodynamic and structural analyses to provide accurate physical information to the conceptual design process. This paper describes the tools, framework and approach used to combine OACD with high-fidelity CFD and CSM analyses and illustrates the first results of its application to design a HAR-SBW aircraft concept which are compared to a conventional tube-and-wing aircraft designed for the same mission.

With the increase in the air traffic, reducing the aviation environmental impact is the key challenge of the community. This has called for more research in the area of using alternative fuels which will reduce the greenhouse gas emissions and which can provide similar or better environmental performance. This work presents a preliminary design methodology of a mid-range single aisle commercial aircraft using Hydrogen as fuel which is stored in an integrated tank in the fuselage. The iterative design process was achieved by using overall aircraft design approach through the FAST-OAD open-source software. This study describes the models used for a first approximation of structural and insulation weight of liquid Hydrogen (LH2) tank and fuel boil off computations. It then presents the impacts of an LH2 storage system on the overall aircraft design with an emphasis on the centre of gravity (CG) travel and the additional fuselage length necessary to accommodate the LH2 tank. An additional parametric study has also been carried out to understand the effect of some design parameters on overall design. Finally, an environmental study has been conducted to evaluate the direct emissions of this aircraft in operation. The only emissions that result from the combustion of hydrogen are nitrogen oxides (NOx) which were evaluated using the Boeing Fuel Flow Method (BFFM2) and water vapor (H2O) which was evaluated based on the fuel burned. As a result of this study significant reduction in NOx and CO2 emissions as compared to existing design are envisaged, thus showing the promising potential of Hydrogen fuelled aircraft.