Numerical Research on the Impact of Sloshing Frequencies of a Liquid Hydrogen Tank Under Massive Heat Leakage Conditions

Hydrogen energy has great potential for wide utilization due to its considerable mass and energy density. However, liquid hydrogen (LH2) tanks are subject to sloshing due to repetitive acceleration and vibration, which can be abstractly described by a sinusoidal oscillation. In this study, we investigate the dual influence of sloshing and massive heat leakage on tank performance under such dangerous situations. Applying the multiple-layer isolation (MLI) method, the 40 ft ISO LH2 tank we chose is assumed to be exposed in the atmosphere of 293K at 1 atm. The content of the liner is liquid hydrogen of 20.3K with a 50% filling level. The whole tank endures 115.431W heat leakage, and all physical features of hydrogen are obtained from NIST. Based on the \(k - \varepsilon\) model and an optimized Hertz-Knudsen equation, a well-validated numerical model is developed to investigate the hydrodynamics and thermodynamics performance of the tank. Five different types of longitudinal sinusoidal oscillation are set and imposed on the Cartesian meshes successfully. The heat leakage for all cases is set to 100 times the normal condition. The results show that the pressure-increasing rate drops and then slightly climbs up with the increase in frequency. In the stationary condition, the pressure-rising rate is approximately 80.999 Pa/s, which in the case of 40% of natural frequency are reduced to 14.89% respectively. In terms of temperature, the maximum increments in the gas phase are influenced by sloshing, as the case of 40% of natural frequency reduces the increment of temperature in gas region. Besides, in a vacuum loss emergency at 50% filling level, drivers have over 5000 s before pressure hits the safety valve's release threshold. This investigation predicts LH2 evaporation in sloshing and insulation failure tanks. It also provides advice for emergency assistance and road-driving strategies as well as a reference for designing cryogenic fluid containers and release equipment.