Development of design methodologies on the trailing edge architecture and application of variable camber to a segmented flap system

Enhancing the efficiency of commercial aircraft is crucial in the context of the global climate change in order to reduce the share of the environmental impact of aviation. The optimization of aerodynamic characteristics offers great potential for saving fuel and reducing emissions. In addition, technologies that can respond to climate-optimized flight altitude variation by adapting the wing geometry during flight become more important in the future. The aim of this thesis is to investigate variable camber principles applied to a segmented trailing edge flap on the overall aircraft level. Furthermore, methods need to be developed that allow the trailing edge flaps, which are essential for variable camber, to be precisely modeled in the preliminary aircraft design stage. Moreover, the thesis introduces a new methodology to ensure valid longitudinal trimming in the iterative design process. To achieve this, a set of methodologies will first be developed for the design of control surfaces, which will later incorporate variable camber. This development includes the optimization of high-lift configurations, the modeling of flap loads in different flight regimes, and the design of actuators. Depending on the application, techniques such as neural networks, fluid simulations, or regression models from existing data are employed. Subsequently, variable camber is applied as a retrofit design to segmented trailing-edge flaps within the preliminary aircraft design environment MICADO of the Institute of Aerospace Systems of the RWTH Aachen University. In order to classify the potential for fuel savings calculated for a variable camber application, the given reference aircraft is compared with an optimization of the twist distribution and finally with a combined application. High predictive accuracies have been demonstrated for all developed models and methodologies, considering the limited data availability at the preliminary design level and the available computing time. At the overall aircraft level, the potential of a variable camber application varies by aircraft type, with a 3.5 % reduction in fuel consumption when applied to an aircraft with a previous wing twist optimization. The segmentation of trailing edge flaps shows a slight but noticeable fuel savings potential, depending on the reference aircraft under investigation. The increase in fuel savings potential is particularly relevant when aircraft operate outside their design optimum. This aspect might become increasingly important for minimizing the climate impact of existing aircraft by altering flight routes to alternative altitudes, such as to avoid the formation of long-lasting contrail-induced cirrus clouds.