Inspired by the vision of emission-free air transport, in 2011, the Bauhaus Luftfahrt research team launched an interdisciplinary design project. As a result, a revolutionary concept for a universally electric passenger aircraft dubbed “Ce-Liner” was developed.
190 seats, 900 nautical miles – zero in-flight emissions
Aircraft with 180 to 200 installed seats dominate commercial aviation today by market volume. With its 190 seats installed, the Ce-Liner fits perfectly into this category. The range electric flight is strongly dependent on the available battery technology. A minimum range of 900 nautical miles was deemed feasible for a medium-sized passenger aircraft. This stage length means a possible market coverage of 79 percent of all flights. The Ce-Liner was designed for a cruising altitude of 33,000 feet and a cruise speed of Mach 0.75.
Innovative, self-trimming C-wing design
- ensures high aerodynamic efficiency to compensate for the higher wing span required due to the significantly increased weight and therefore larger wing area of an all battery-powered electric aircraft,
- constantly adapts its shape using morphing techniques to optimise flight conditions.
Universally-electric energy and propulsion system
- with two ducted fans driven by high-temperature superconducting electric motors, supplied by advanced lithium-ion batteries,
- a required specific energy for the batteries of 2,000 watt hours per kilogramme, roughly eight to ten times higher than state of the art in 2011,
- up to 16 battery modules installed in specially adapted LD3 cargo containers known as Charge Carrying Containers (3C).
The aircraft’s key technologies, system configuration and overall layout
On the one hand, a full-electric approach including electromotive power offers new degrees of freedom with respect to system integration on board the aircraft. On the other hand, the handling characteristics on the ground, especially the turnaround times, require easy access to the battery packs.
- Recharging the batteries during turnaround is postulated to remain challenging; hence an exchange after each flight is assumed.
- The motive power system‘s electric motors as well as the power transmission system‘s bus are to be equipped with high temperature superconducting technology (HTS), which is expected to deliver a high power-to-weight ratio by the time of the entry into market.
- Aerodynamic efficiency is improved by a non-planar wing configuration, the so-called C-wing. It offers an enhanced performance for given geometrical constraints imposed by airport compatibility, for instance wing span limitations.
- Another aspect was the economic considerations of the potential operators. The chosen concept needs to outperform any competitors in terms of operating cost and direct maintenance.
- In addition, a well thought-out cabin layout was designed using passenger data for the year 2035+, taking into account the expected trend towards taller passengers in a modified setup of seats, aisles and storage bins.
New ways of cooperation in the design process
Challenged by the enormous task, the group also chose new ways of working together in the design process using "agile methods". Especially the so-called Scrum process proved to be very valuable for mastering the highly dynamic and interdisciplinary tasks and enabled a flexible response to the numerous changes in requirements without quality deficiencies or budget overruns