The aviation industry contributes approximately 3.5% to total man-made climate forcing, with air traffic expected to double between 2023 and 2042.
This growth exacerbates the sector’s climate footprint, underscoring the urgency for sustainable alternatives. Recent studies indicate that a combination of low-carbon fuels and advanced technologies could address 80% of the measures necessary for achieving carbon-neutral growth in aviation. Among the various alternatives, liquid hydrogen (LH2) emerges as a promising solution for decarbonizing long-range aviation, particularly when integrated into blended-wing-body (BWB) aircraft designs.
Research conducted by Imperial College London highlights the potential of LH2 aircraft to reduce specific energy consumption (SEC) significantly—by 51.7-53.5% compared to traditional Jet-A powered aircraft like the Boeing 777-200LR. This reduction stems from LH2’s lower weight and higher energy density, which can decrease thrust requirements and improve overall aerodynamic performance. However, the lower volumetric energy density of LH2 poses challenges, particularly in aerodynamic performance and energy consumption when applied to conventional tube-wing designs.
The adoption of BWB configurations facilitates better integration of LH2 storage due to their enhanced aerodynamic characteristics and increased internal volume for cryogenic systems. This design shift is essential as it allows for improved fuel efficiency and operational flexibility, vital for meeting future aviation demands. The energy performance modeling indicates that future LH2 BWB aircraft could achieve substantial efficiency gains, particularly under varying load factors and ranges.
A recent analysis by Swapnil S. Jagtap, Peter R.N. Childs and Marc E.J. Stettler, was published in the International Journal of Hydrogen Energy.
The technical specifications of future LH2 BWB aircraft are also noteworthy. The conceptual design includes ultrahigh bypass ratio geared turbofan engines, which are expected to operate at reduced thrust levels while maintaining efficiency. The study indicates that by optimizing weight and thrust ratios, these aircraft can achieve operational efficiencies that align with stringent environmental targets.
Despite these advancements, several challenges remain unaddressed in existing literature regarding LH2 aircraft design and performance. Notably, many studies fail to provide comprehensive design metrics or detailed comparisons between LH2-powered BWB aircraft and their Jet-A counterparts. Furthermore, while some research explores various alternative fuel options, a thorough quantitative evaluation of LH2’s lifecycle impacts remains limited.
