TY  - EJOU
AU  - Jin, Dapeng 
AU  - Wang, Yuejiao 
AU  - Liu, Bin 
AU  - Zhang, Yichi 
AU  - Zhang, Sichao 
AU  - Yin, Pengbo 

TI  - Sequential Modeling of Liquid Hydrogen Leakage, Dispersion and Post-Ignition Thermal Hazards in Semi-Open Railway Stations
T2  - Fluid Dynamics \& Materials Processing

PY  - 
VL  - 
IS  - 
SN  - 1555-2578

AB  - This study develops a sequential numerical modelling framework to elucidate the transient evolution of liquid hydrogen (LH<sub>2</sub>) leakage, pool evaporation, hydrogen dispersion, and post-ignition thermal hazards in a representative semi-open railway station. The framework couples a source-term integral model for LH<sub>2</sub> pool evaporation with computational fluid dynamics (CFD), in which the time-dependent liquid-pool radius and evaporation mass flow rate are introduced as transient inlet conditions through a user-defined function. The Realizable <i>k</i>-<i>ε</i> turbulence model and species transport equations are employed to predict the subsequent dispersion of gaseous H<sub>2</sub> within the station environment, accounting for the influence of large-span roofs, locomotives, and structural columns on hydrogen migration and retention. At 3.0 s after leakage initiation, the analysis branches into non-ignited dispersion and ignition/combustion scenarios. For the latter, the instantaneous H<sub>2</sub> concentration, temperature, and velocity fields are used to initialize ignition at (−0.7, −3.6, 0.5) m. The results show that the LH<sub>2</sub> evaporation mass flow rate reaches approximately 3.6 kg/s at 3.7–3.8 s, while the liquid-pool radius increases to approximately 1.2 m at 4.2 s. In the non-ignited scenario, the 4 vol% H<sub>2</sub> cloud reaches a front position of 22.42 m and a length of 28.92 m at 9 s, while residual hydrogen continues to migrate and dilute for approximately 200 s. In the ignition/combustion scenario, the maximum flame temperature reaches 2193.5 K at 3.0 s. The combustion analysis is limited to post-ignition thermal effects and does not consider deflagration-induced overpressure or structural response.
KW  - Liquid hydrogen leakage; transient source term; hydrogen dispersion; thermal hazard; railway station

DO  - 10.32604/fdmp.2026.089244