CFD Modelling of Liquid Hydrogen Containment

Accurate prediction of pressurisation and sloshing in cryogenic containment tanks is critical for reliable tank pressure control. This work validates the in-house Elemental® AlphaFlow commercial software against two benchmark liquid hydrogen (LH2) experiments: the recent SHIIVER (Johnson et al. 2024) passive pressurisation test and the pressure collapse due violent slosh of Moran et al. (1994). Simulations are preformed using real and ideal gas models coupled with an incompressible Boussinesq liquid approximation. Suitability of the gas models for the experimental conditions is assessed. For SHIIVER, the 70% fill-level passive pressurisation case is for the first time simulated. Notably, a thin wall conjugate-heat-transfer model is used to capture the redistribution of heat flux between the liquid and vapour regions with its validity verified via wall Biot number analysis. Interfacial heat and mass transfer are resolved using a sharp-gradient based method which is also applied to the mass transfer calculation. Predicted pressurisation rates agree with experimental data to within 2% on a coarse grid and 1% on a f ine grid demonstrating grid convergence and accurate thermal-fluid wall coupling. For the violent slosh case, the 36% fill level case is modelled. No phase change nor conjugate-heat-transfer effects are included. Here, a calibrated Smagorinsky-Lilly Large Eddy Simulation (LES) based on a Reynolds & Nusselt number correlation is employed to capture the turbulent interfacial heat transfer.