\label{cha:concl} This report explains the process that was made in the early conceptual design and the conceptual design during the design process of an innovative, sustainable and electrical racing aircraft of the future. It describes the trade-off process that lead to the final configuration and defines the subsystems that can be used.
Based on the identified risks and requirements, and through analysing the existing and the future market, the focus of the project was set to lie in the development of a prototype of an electrical aircraft that can perform in a Red Bull Air Race and compete with or outperform the currently participating aircraft. 8 design configurations were identified, based on their wing layout and their propulsive distribution. From these, a conventional configuration, a canard and a biplane were traded off and further improved by trading off subsystems for the individual configurations. Thereafter, another trade-off was performed to find the best of the three designs for the stated mission objective. The canard was selected.
The canard was deemed superior to the other configurations mainly because of its beneficial maneuverability that results from both lifting surfaces, the wing and the canard, generating positive lift. The design can therefore perform sharp high g-load turns very fast and is expected to thus achieve good track times air races. The canard configuration features several subsystems that are presented in the following.
Wing: A rectangular wing with a low aspect ratio and a low taper; e.g. a taper between 0.45 and 1.
Wingtips: Hoerner tips or wing tips that allow for yaw control.
Canard: The canard far forward, mounted to the fuselage.
Propulsion system: An open, contra-rotating propeller.
Landing gear: A fixed trycicle configuration.
Battery: The aircraft is powered by a Lithium-Sulfur battery system.
This design configuration was analysed in detail and an internal and external layout was created. Unforeseen problems with the current subsystems may still change the configuration slightly. Therefore, a sensitivity analysis was performed. It was determined that aspects of the canard design could still be altered without undermining its ability to perform in races. Furthermore, a stability and control analysis, an analysis of the aerodynamic characteristics and a track analysis was performed. Thereby, a first approach to an airfoil selection is taken. It is expected that the final design will have a modified 4-digit NACA airfoil for both the main wing and the canard.