At ILA Berlin 2022, Bauhaus Luftfahrt revealed three vision- ary concepts for hydrogen-fuelled airliners covering all the key market segments in commercial air transport – the regional, short-range, and long-range aircraft classes. While the basic transport tasks for the regional and short-range cases were defined in accordance with the CleanSky aircraft specifications, the long-range application was derived from Bauhaus Luftfahrt’s Hyliner 2.0.
All three aircraft concepts featured carefully configured sets of technologies in order to best support the use of liquid hydrogen (LH2) as the primary source of on-board energy.
Most notably, the propulsion systems were tailored to the specific needs and challenges of each power class: The regional aircraft uses high temperature polymer electrolyte fuel cells to power the aft-fuselage podded propellers. The long-range aircraft features two under-wing podded geared turbofan engines equipped with Composite Cycle Engine cores. An aft-fuselage integrated fuel cell system provides electric power to the boundary layer ingesting fuselage fan.
The fuel cell product water is recycled and injected in the gas turbine engines in order to improve performance and emission characteristics. A similar fuel cell-gas turbine hybrid with product water recovery is also used within the short-range aircraft, however, featuring a 50 / 50 power split and a single gas turbine installed inside the aft-fuselage.
Initial energy efficiency assessments clearly indicate the potential for these individual propulsion concepts to eliminate the LH2-related drag and empty weight penalties in all three aircraft classes effectively.