Design and Optimization of a Compliant Morphing Trailing Edge for High-Lift Generation

This work focuses on the design and optimization of a morphing-compliant system developed within the project HERWINGT (Clean Aviation) and aimed at generating high lift during take-off and landing. The device was conceived to replace a conventional flap of a regional aircraft and work in synergy with a droop nose and a flow control system. The architecture is based on a compliant layout, specifically selected to obtain a final morphed shape of the trailing edge of the wing efficient for high-lift purposes and adequately smooth even in cruise clean configuration. At first, the requirements at aircraft level were critically examined and then elaborated to produce the specifications of the morphing device. A layout was then sketched, considering on its potential in approaching the target morphed shape and on its intrinsic criticalities. Starting from this scheme, a simplified FE model was introduced. The scope was to have an efficient predictive tool suited for optimization processes. After having identified the most relevant design parameters (skin thickness distribution, topology of the structure, and actuator interface parameters), the cost function, and the constraints of the problem (structural integrity and stability), a genetic optimization was implemented. Repeating the genetic process starting from different initial populations, some optimized configurations were identified. A trade-off was thus organized on different criteria, such as the lightness of the structure, the load-bearing capability, the force, and the stroke needed by the actuator. The best compromise was finally taken as baseline for the realization of an advanced FE model used to validate the numerical outcomes obtained during the optimization process and as starting point for the next steps planned in the project. The achieved design is characterized by an enhanced aerodynamic performance with the absence of steps and gaps and external track fairings, reduced weight of both the structure and the actuator, reduced maintenance costs due to a simple layout, and smaller take-off and landing distances owing to the high-lift capability and the intrinsic lightness.