Computational Fluid Dynamics Modelling of Liquid Hydrogen Behaviour in Insulated Tanks

A crucial part of the green transition is finding new ways to store and transport energy without contributing to greenhouse gas emissions. Hydrogen is a promising candidate, as it can be used to store energy in various forms, such as in ammonia, as compressed gas, or as a liquid at extremely low temperatures (-250 degrees Celsius). The latter, often referred to as LH2 (liquefied hydrogen), is seen as a promising option for international hydrogen transport. Due to the low temperature, highly effective insulation is necessary to minimize the evaporation of LH2, as this would lead to pressure build-up in the tank. However, even with the most advanced insulation materials, some heat will always seep through the tank walls. Understanding and predicting how much evaporation this heat causes under different scenarios is critical for developing efficient, and above all, safe infrastructure for LH2 transport. In my PhD work, I use Computational Fluid Dynamics (CFD) to simulate the evaporation of LH2 in cryogenic tanks. Accurate modeling of LH2 is highly beneficial since experimental testing is very complex and costly due to the low temperature and the highly flammable gas formed when LH2 mixes with air. In the first part of my research, I investigate how heat affects the flow and heat transfer in the gas phase of spherical LH2 tanks. This can be used to estimate how much liquid evaporates and how hot the evaporated gas becomes, which is important for managing the gas in the best possible way. In the second part of my PhD, I plan to explore gas-liquid simulations in more detail and see how different scenarios affect evaporation on a smaller scale. These scenarios include sloshing (which occurs when tanks are in motion) and pressure reduction boiling (flash boiling).