Thermodynamic performance on the pressurized discharge process from a cryogenic fuel storage tank

Abstract

Due to excellent performance, cryogenic propellants, such as liquid hydrogen and liquid oxygen, are widely used in aerospace engineering. However, low storage temperature and low kinetic viscosity bring a lot of technique issues for high efficient thermal management on cryogen. An actual cryogenic fuel storage tank is selected as the research object, and a two-dimensional axial symmetrical computational model is established to study the pressurized discharge process, by adopting the volume of fluid (VOF) model. Both external environment heat leakage and the heat exchange occurring between the liquid and vapor are considered. Compared to the experimental results, the relative error is limited in 20.0%. Based on the developed numerical model, the temperature variation and heat flux through the insulation and tank wall, the pressurized discharge performance and the fluid temperature distribution are analyzed. The results show that during the pressurized discharge process, the lowest temperature appears in the inner side of the foam, and the external heat invasion does not absolutely penetrate into the tank. The vapor mass experiences fluctuating variations, and the vapor is always in condensation. In the first 200s, the temperature of the outflow fluid keeps constant, and then increases gradually. Under the present initial setting, the violent boiling phenomenon does not form during the whole process. The present study is significant to the depth understanding on the pressurized discharge of cryogenic fuels. • The lowest temperature appears in the inner surface of the foam with high-temperature gas occupied. • The external heat invasion does not penetrate into the tank during pressurized discharge. • The vapor is condensed by the subcooled liquid, and its mass experiences fluctuating variations. • The outflow pressure is higher than the saturated pressure, and the violent boiling does not form.