Thermodynamic performance in a liquid oxygen tank during active-pressurization under different gas injection temperatures

In this study, a numerical model is developed to investigate the active-pressurization performance in a liquid oxygen tank. The VOF method is used to predict the thermal behavior in the liquid oxygen tank with consideration of interface phase change. The numerical model is validated against the experimental results with relative error < 5%. The effect of the gas injection temperature on the tank thermal behavior is investigated. The results show that the tank pressure-rise rate with the injected gas temperature, but the time consumption of the tank pressure-rise decreases with the injected gas temperature. High gas injection temperature leads to intensive pressure fluctuations. The liquid evaporation is the main phase change mode in the first 2 min, thereafter the vapor condensation becomes prominent. The vapor condensation capacity increases with the total gas injection mass, and the minimum gas injection mass and vapor condensation capacity are obtained with the injected gas temperature of 320 K. The gas injection causes disorder temperature distribution in the vapor, and promotes the thickness increase of the thermal stratified layer. The injected gas temperature has slight influences on the development of the thermal layer, but it effectively enhances the temperature rise of the interface liquid. The present work is significant to depth understanding on the tank active pressurization and could supply some technique references for the design and optimization of cryogenic propellant system.