Numerical Simulations of Experimental Fireball and Blast Wave from a High-Pressure Tank Rupture in a Fire

Hazards from the fireball and blast wave after high-pressure hydrogen tank rupture in a fire are not yet fully understood. The contemporary tools like CFD are not yet validated against experimental data to be used as a reliable predictive tool for such catastrophic failures. In this study the experiment with high-pressure hydrogen storage tank rupture in a fire, followed by a blast wave and a fireball, was numerically simulated. The applied CFD model includes the eddy dissipation concept (EDC) sub-model for combustion incorporating a detailed chemistry with 37 chemical reactions, and the RNG k-epsilon sub-model for turbulence. The model has been recently successfully applied to simulate experimental data on spontaneous ignition of hydrogen during the sudden release into the air, and different indoor jet fire regimes. In this study, the results of the simulations are compared against experimental data on a high-pressure (35 MPa) stand-alone hydrogen tank of volume 72.4 l rupture in a bonfire test. The simulation results are compared with predictions of the analytical model too. The CFD model gives insights into the dynamics of the blast wave and the fireball to assess the hazard distances. The simulations reproduced well experimental parameters such as blast wave decay, overpressure dynamics at different distances, including the timing of the blast wave arrival, fireball shape and size.