Boiling Liquid Expanding Vapor Explosion of liquid hydrogen

This thesis focuses on the modelling of liquid hydrogen Boiling Liquid Expanding Vapor Explosions (BLEVEs). This terminology identifies a catastrophic release of this unconventional fuel following the loss of its containment. The present work aims to enhance the knowledge on the consequences of such explosions, using the data collected from crucial experiments to validate the simulations. The consequence analysis of the "SH2IFT Project" and the ”Bursting Tank Scenario” experimental BLEVEs is carried out simulating the explosions to verify the reliability of the implemented physical models. To complete the modeling of the catastrophic rupture of liquid hydrogen (LH2) tanks, the combustion process is taken into account to describe the aftermath of the simulated accidents in terms of overpressure and impulse. Furthermore, it is also discussed the possible involvement of the endothermic reaction of the hydrogen para-isomer converting into its ortho-isomer form. In this way, a further validation and confrontation between the models currently used for conventional liquid fuels like propane and liquefied petroleum gas (LPG) is possible, adopting and adapting them to the specific case of a liquid hydrogen catastrophic release. So, it is possible to consider this thesis as divided in three major steps: the first one is the analysis of the physical explosions with the proposed models, the second one is the adaptation of such models to take hydrogen combustion into consideration and the third and last one is an analysis of the para-ortho reaction which may follow the explosion. At the end, a confrontation between the experimental data and the proposed calculations is carried out, underlining the aspects which still require further studies, experiments and documentation.