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针对液氧贮箱氦气增压排液过程,分别建立了零维整体模型、一维分层模型及二维计算流体力学(CFD)模型对气枕物理场的变化规律进行数值研究.零维及一维模型采用经验公式求解气枕与壁面间的换热量,而二维CFD模型通过低雷诺数k-ε模型确定流体与固壁间的耦合换热作用.计算时氦气采用理想气体模型.利用三种模型分别预测了贮箱内气枕压力、气枕平均温度及温度分布规律.计算结果表明:三组结果分布合理,不同模型的结果之间能够互相印证;对于气枕及与气枕接触壁面沿轴向的温度分布,在气枕主体区一维模型与二维模型预测结果基本吻合,而在靠近消能器的气枕上端,两种模型预测值存在偏差;当增压气体入口速度较大时,气枕上端径向温度分层明显,需采用二维CFD模型才能展示气枕物理场分布.
According to the helium pressurization and drainage process of liquid oxygen storage tank, the zero-dimensional overall model, one-dimensional layered model and two-dimensional computational fluid dynamics (CFD) model were respectively established to study the changing law of the physical field of the gas pillow. And the one-dimensional model uses the empirical formula to solve the heat exchange between the pillow and the wall, while the two-dimensional CFD model determines the coupling heat transfer between the fluid and the solid wall through the low Reynolds number k-ε model. Model.The three models were used to predict the pressure distribution of the air pillow, the average temperature of the air pillow and the temperature distribution respectively.The results show that the distribution of the three groups is reasonable and the results of different models can confirm each other.For the air pillow and The temperature distribution along the axial direction of the contact surface of the air pillow is basically consistent with that predicted by the two-dimensional model in the main area of the air pillow, while the prediction values of the two models are biased at the upper end of the air pillow near the energy absorber. When the gas inlet velocity is large, the radial temperature at the upper end of the air pillow is obviously stratified, and the two-dimensional CFD model is required to display the air pillow physics distribution.