Development and optimization of novel morphing wings for the next-generation aircraft

Abstract

The aeronautical industry has aimed to reduce its carbon emissions in this era of global warming by adopting various new strategies and technologies. Achieving reduced fuel consumption by aircraft would directly contribute to this goal. Improving the next-generation fleet of aircraft by using these new technologies paves the way for achieving green aviation's ultimate goal of an environmentally friendly aviation industry. This thesis explores nextgeneration wings in the framework of promising morphing wing technology, with the objective of enhancing aircraft aerodynamic performance and efficiency. This research focuses on innovative morphing approaches that could be applied on wings’ trailing edges. Two novel morphing approaches are introduced: the Seamless Morphing Trailing Edge (SMTE) flap, and the twist morphing ailerons and winglet design. The former replaces the conventional main flaps of an aircraft, and the latter replaces the conventional ailerons of a UAV. For this purpose, 3D aerodynamic shape optimization is performed for each morphing approach using a high-fidelity gradient-based optimization algorithm with a high-fidelity flow solver, OpenFOAM. The framework is based on an object-oriented adjoint-based Open-Source code called DAFoam and uses the Free-Form Deformation (FFD) parametrization technique. FFD is an efficient method in 3D optimization, where 100s or 1000s of design variables are considered in a full wing or a full-scale aircraft optimization. A suitable objective function specifies each morphing approach according to the mission objectives and flight conditions. Optimization of SMTE flaps for different flight conditions and regimes, including climb, cruise, and gliding descent is conducted using a high-fidelity steady-state aerodynamic shape optimization. A comparative analysis with the results from conventional hinged flaps demonstrates the morphing flap's superiority; indicating up to 3.8% power reduction and a 6.13% increase in climb rate. The SMTE flap also enhances aerodynamic efficiency by up to 17.8% and extends laminar flow on the wing's upper surface compared to a conventional hinged flap. In addition, a 61.2% gain was achieved for endurance improvement compared to that of a clean wing configuration. Finally, the optimized configuration for gliding descent achieved a 43% reduction in the descent rate. Another high-fidelity gradient-based aerodynamic shape optimization is performed to improve rolling efficiency and reduce induced drag by introducing a novel twist morphing aileron and winglet design. The twist morphing increased the aileron efficiency by 34% and reduced induced drag by 61% compared to a conventional aileron design. In more detail, twist morphing winglets reduced the induced drag by 25.7% in cruise flight, by 16.51% in climb, total drag by up to 7.5%, and overall, enhanced aerodynamic efficiency by up to 9%. After obtaining promising aerodynamic improvements for an SMTE flap, the study continues by proposing the novel Elephant Trunk Mechanism (ETM), a bio-inspired morphing concept derived from an elephant's flexible and versatile trunk. Structural analysis and topology optimization is performed to examine the feasibility and practicality of the proposed mechanism. The ETM employs tooth-like elements attached to a solid wing box, actuated by wire cables, to achieve smooth downward bending deformation of the trailing edge. Both Finite Element Analysis (FEA) and topology optimization ensure the structural feasibility and stability of the ETM, leading to a reliable and lightweight morphing mechanism. Finally, an experimental analysis is performed by prototyping the SMTE flap equipped with an Elephant Trunk Mechanism to validate the results obtained from aerodynamic and structural studies. This study is orientated towards the development of morphing trailing edge flaps, but more importantly, it confirms the promising benefits of the SMTE flap in terms of aerodynamic performance and structural feasibility. These studies demonstrate the potential of morphing wing technologies to significantly improve an aircraft's performance, efficiency, and maneuverability, paving the way for their practical implementation in next-generation aircraft.

Date	31 Jul 2025
Original language	American English
Awarding Institution	École de technologie supérieure
Supervisor	Ruxandra Botez (Supervisor)