Tube-and-wing aircraft for the year 2050 timeframe
Within the EU-funded project “ULTIMATE”, new propulsion-related technologies were investigated. To assess new designs, reference aircraft for a year 2050 entry into service were necessary. Therefore, a short- to medium-range and a long-range aircraft were designed using an evolutionary approach and utilising an open rotor and a geared turbofan engine, respectively. The conducted technology screening found suitable technologies to increase performance with the target of achieving Flightpath 2050 goals. Finally, a synergistic set of technologies was selected in order to reduce weight and drag of the airframe. The technologies used include an all-electric subsystem architecture (Fig.) powered by a fuel cell. This enables electric taxiing and lowers CO2 consumption. Further technologies were included, for example hybrid laminar flow control, with the aim of drag reduction. Moreover, it was strongly emphasised to use synergistic effects of incorporated technologies. For example, the variable camber system provides not only a wide range of different optimised air-foil geometries during cruise flight, but also enables favourable flight condition-specific pressure distributions to increase transition length from the hybrid laminar flow control system as well as load alleviation capabilities. Overall, the designs are capable of reducing fuel per passenger and distance by 47 % for the long-range version and almost 60 % for the short-range design. While these are impressive values, they are not sufficient to reach the Flightpath 2050 goals, emphasising the necessity of radical engine and aircraft architectures.
- Model of the all-electric subsystem: The electric subsystem architecture is capable of supplying all systems through a fuel cell. Generators at the engines ensure redundancy and drive the fan/rotor to enable electric taxiing.
- Family design of the reference aircraft related to existing aircraft: The designed aircraft concepts fit in with current designs, but show the trend for higher seating capacity and range in the short-range segment.