On the Structural Design of a Hydrogen-Powered Commuter Configuration with Distributed Electric Propulsion in the Context of a Multidisciplinary Conceptual Workflow

The aeronautical industry is facing a fundamental transformation. Climate change and plain finiteness of fossil resources necessitate a strategic shift in the transportation sector while being confronted with an ever-growing demand. Airborne traffic, in particular, is vulnerable, due to its dependency on dense and efficient energy storage. Popular fossil alternatives, like fully electric or hydrogen powered, while promising in terms of reduction in emission of climate active gases suffer from increased complexity and - so far - worse energy density. To face these challenges in an interdisciplinary manner, the German Aerospace Center (DLR) founded the Facility for Small Aircraft Technologies as a collaborative research platform on climate neutral aviation. As part of this part of this initiative, the project D-LIGHT+ aims to develop a hybrid electric commuter class aircraft featuring distributed propulsion and hydrogen powered fuel cells. This project combines the expertise in conceptual aircraft design, fuel cells, carbon fibre hydrogen tank design, electrical power trains, and loads analyses and optimization of load carrying structures. Furthermore, the project aims to compose a highly automated design workflow, interlinking the various disciplines, while accounting for their interdependency and various levels of fidelity. This work focuses on the design of the primary lifting surfaces, with an emphasis on their structural design. Consequently, the challenges posed to the loads and optimization process emerging from the highly automated and intertwined workflow in combination with the deviation from classical aircraft design are discussed. The presented approach includes a semi-automated process for placement of topological components, the generation of distributed mass models using information provided by the partners, aeroelastic load analyses, as well as the generation of optimization models for the load carrying structures. In this context, software for generating structural optimization models is presented and the results of topology studies are discussed. Finally, the impact of the topological findings and structural optimization on the overall aircraft design is assessed.