The adoption of liquid hydrogen (LH₂) as a sustainable aviation fuel presents unique challenges, particularly regarding fuel tank dynamics during flight. Sloshing-induced thermodynamic changes in cryogenic tanks can significantly impact pressure stability and fuel management systems. This study addresses the critical need to model and understand these complex interactions to ensure safe and efficient LH₂ storage in dynamic flight environments.
An integrated computational framework was developed using Cranfield University's in-house thermal-fluid code as the foundation. Ludwig's thermal diffusivity model, originally validated for liquid nitrogen (LN₂), was adapted from a temperature-based to an energy-based approach and incorporated into the thermal-fluid model to capture sloshing dynamics. The enhanced model underwent validation against experimental LN₂ data before being applied to LH₂ systems under the assumption of similar cryogenic fluid behaviour. A comprehensive three-phase methodology encompassed validation, LH₂ case studies, and parametric analysis examining initial pressure, fill levels, and excitation characteristics.
Model validation achieved agreement with experimental data, showing maximum deviation of only 7%. LH₂ simulations revealed a sloshing-induced pressure drop of approximately 100 kPa over 40 seconds, attributed to enhanced condensation and turbulence at the liquid–vapour interface. Parametric analysis demonstrated that higher initial pressures and fill levels (85%) increased pressure drop rates by 5-8%. Notably, chaotic sloshing patterns produced substantially faster pressure decrease (5.2 kPa/s) compared to planar wave sloshing (3.2 kPa/s).
This research demonstrates the capability of the enhanced thermal-fluid model to simulate complex cryogenic tank behaviour under dynamic conditions. The findings provide valuable design insights for optimizing LH₂ tank configurations and operational strategies in future hydrogen-powered aircraft, contributing to the advancement of sustainable aviation technologies.
