Conceptual investigation on performance of short-medium range aircraft with liquid hydrogen propulsion and different airframe architectures

The present paper deals with the design and performance assessment of short-medium range transport aircraft with liquid hydrogen (LH2) propulsion. The proposed procedure has been set-up following a retrofitting approach, with the aim of investigating in depth the effects of integrating hydrogen propulsion systems in aircraft with known characteristics. By means of such approach, it has been possible to investigate the sensitivity to some main performance indicators, namely: the transport capabilities of the retrofitted aircraft, in terms of maximum payload and maximum ranges achievable; the parameters related to the integration of the hydrogen propulsion systems, such as the LH2 consumption or the tanks mass. An exhaustive presentation of such sensitivity analyses is reported and discussed, focusing on the differences between tube-and-wing and box-wing airframe architectures. For both the airframes, two different cases of LH2 tanks integration have been investigated, by considering, or not, the presence of a catwalk. The results have shown that box-wing hydrogen aircraft shows similar transport capabilities, i.e. range and number of passengers, in both cases; on the other hand, the presence of catwalk reduces the transport capabilities of tube-and-wing aircraft. In general, for both the configurations a reduction in number of passengers needs to be taken into account to provide the proper space into the fuselage to store the LH2 tanks; however, in this conceptual stage, these penalisations seem to be acceptable, as the benefit in terms of CO2 reduction is prevalent.