Simulation of the Refuelling Process for an LH2-powered Commercial Aircraft Part 1 - Modelling and Validation

Liquid hydrogen (LH2) is a promising candidate for zero emission aviation, but its cryogenic properties make the refuelling process fundamentally different from that of conventional jet fuels. Although previous studies have addressed LH2 storage and system integration, detailed modelling of the refuelling process remains limited. This paper presents the first part of a two-part study focused on simulation of the refuelling process for an LH2-powered commercial aircraft. An existing tank model is substantially modified to more accurately capture relevant physical phenomena, including heat transfer and droplet dynamics during top-fill spray injection. Newly available experimental data on LH2 no-vent filling enables direct validation of the model under conditions that match the experimental setup. A sensitivity analysis identifies the most influential parameters that affect model precision, including loss coefficient, droplet diameter, radiative heat ingress, and vent-closing pressure. The validated model forms the basis for Part 2 of this study, in which it is applied to a representative LH2-powered commercial aircraft to simulate refuelling times, quantify venting losses, and assess the impact of key operational settings. These results support the design of efficient LH2 refuelling systems for future aircraft and airport infrastructure.