Conceptual Design-optimisation of a Subsonic Hydrogen-powered Long-range Blended-wing-body Aircraft

The adoption of liquid hydrogen (LH2) holds promise for decarbonising long-range aviation. LH2 aircraft could weigh less than Jet-A aircraft, thereby reducing the thrust requirement. However, the lower volumetric energy density of LH2 can adversely impact the aerodynamic performance and energy consumption of tube-wing aircraft. In a first, this work conducts an energy performance modelling of a futuristic (2030+) LH2 blendedwing-body (BWB) aircraft (301 passengers and 13,890 km) using conceptual aircraft design-optimisation approach employing weight-sizing methods, while considering the realistic gravimetric and volumetric energy density effects of LH2 on aircraft design, and the resulting reduction in aircraft thrust requirement. This study shows that at the design point the futuristic LH2 BWB aircraft reduces the specific energy consumption (SEC, MJ/ tonne-km) by 51.7–53.5% and 7.3–10.8%, compared to (Jet-A) Boeing 777-200LR and Jet-A BWB, respectively. At the off-design points, this study shows that by increasing the load factor for a given range and/or increasing range for all load factor cases, the SEC (or energy efficiency) of this LH2 BWB concept improves. The results of this work will inform future studies on use-phase emissions and contrails modelling, LH2 aircraft operations for contrail reduction, estimation of operating costs, and lifecycle climate impacts.