Comparison of Predictive Performance Between Simple Models and Computational Analysis for High-Pressure Hydrogen Tank Explosion Characteristics

In this study, the overpressure and impulse distribution characteristics of high-pressure hydrogen tank explosions were analyzed using simplified models and computational analysis. Two simplified models, Molkov’s model and the TNT-equivalent method, were employed, and a computational analysis was conducted using the OpenFOAM code with the Reynolds-averaged Navier–Stokes approach. The pressure wave propagated spherically during the explosion of the high-pressure hydrogen tank. However, the interaction with the ground generated a reflected overpressure, which had a significant influence on the radial overpressure distribution. Furthermore, the high-temperature flame region was confined to the vicinity of the explosion source, and the flame was identified as a diffusion flame. The simplified models predicted the maximum overpressures in the radial and axial directions. As the simplified models treat the hydrogen tank as a point source, they predict the same overpressure and impulse values in both the radial and axial directions, which can limit the accuracy of real high-pressure hydrogen tanks with large aspect ratios (length-to-diameter ratios). Computational fluid dynamics analysis showed reasonable agreement for the maximum overpressure of the experimental results in both the radial and axial directions. However, the accurate modeling of the reflected overpressure, particularly at close distances, is critical to improving the prediction accuracy for overpressure and impulse distributions.