Evaluation of a fixed-interface multi-region model for long-term evaporation in cryogenic propellant tanks

Recent booming applications of cryogenic fluids in aerospace engineering, liquefied natural gas industry, and hydrogen energy have accentuated the demands for long-term cryogenic storage. A more comprehensive understanding of cryogenic evaporation in storage tanks has become a priority for reducing boil-off loss, extending storage duration, and guaranteeing container safety. Efficient modeling of interfacial heat transport has become the bottleneck for high-precision prediction of the steady-state evaporation of cryogenic fluids. This study addresses this challenge by developing a fixed-interface multi-region model, to simulate the steady-state evaporation characteristics in cryogenic storage tanks. The fluid domain is modeled as two regions for liquid and vapor phases and a fixed interface. The model is validated to accurately predict the temperature jump at the liquid–vapor interface. An analysis of the interfacial energy transport patterns is also provided. Furthermore, the performance of the fixed-interface model was compared with a VOF model in terms of simulation speed, interfacial temperature, and interface geometry. The results showed that the fixed multi-region model accurately predicted the interfacial temperature distributions, particularly in the vicinity of the liquid–vapor interface compared to the VOF model, while demanding only 3.6 % of the computational resources.