气动加热影响下的液氧储罐内温度分层与相变特性仿真分析

Temperature Stratification and Phase Transition in Liquid Oxygen Tank with Aerodynamic Heating Boundary

采用三维模型数值模拟液氧储箱预增压上升过程,对液氧相变特征以及温度分层发展规律进行了分析。从计算结果可以看出:在气动加热影响下,气液界面液氧蒸发速率在0.012 6kg/s附近振荡;近壁面液氧沸腾速率随时间变化规律与外界漏热量一致,整个过程相变速率平均值为0.086kg/s。随着高温增压气体通过散流器喷射进入气枕空间,液氧温度分层逐渐明显,温度不断升高,预增压183s气液界面处液氧温度从89.51K升高至93.61K,平均温升速率0.022K/s。

Pre-pressurization rise process of the liquid oxygen stored in a tank is simulated through 3D CFD simulations. The phase transformation rate and temperature stratification of liquid oxygen are specified. The results suggest that evaporation rate of the liquid oxygen is fluctuating around 0. 012 6 kg/s under the aerodynamic heating boundary condition. The liquid oxygen boiling rate near the wall is also investigated and averagely reaches 0. 086 kg/s in the whole process, which is consistent with the tank heat leakage. The temperature stratification is observed when the high-temperature gas pressurization enters the tank by a diffuser. The liquid oxygen temperature in the gas-liquid interface increases from 89. 51 K to 93.61 K. The average increasing rate of the liquid temperature is 0. 022 K/s for 183 s after the pre-pressurization.