【摘要】 根据逆环状流膜态沸腾(IAFB)的可视化实验结果,将该流型理想化为一个两区物理模型。按双区物理模型假定,建立二维、二流体数学解析模型。它由质量、动量和能量守恒微分方程以及相应的本构方程构成完全方程组,然后用数值方法求解。用该模型分析了液相、汽相参数以及加热管的壁温,与Stewart的实验数据进行了比较,两者相当一致。可信地预示了液体过冷度、质量流率、系统压力和加热热流率对加热面温度的影响。同时选择实例分析了流动二维效应和初始汽膜厚度取值对加热面温度和膜厚变化的影响。结果表明:在讨论的范围内忽略两维效应对壁面温度影响不大;初始膜厚取值不同对加热面温度变化和膜厚变化无显著影响。更多还原

【Abstract】 A two-dimensional two-fluid model is developed to predict the liquid and vopour parameters as well as the surface temperature of a heated tube. A two regions of physical modeling represents inverted-annular film boiling (IAFB)based on author’s visual observations. The analytical model is consisted of a set of differential conservation equations together with appropriate closure correlations and solved numerically. Successful comparisons are made between model predictions and Stewart’s experimental data. Generally, the model predicts correctly the dependence of wall temperature on liquid subcooling, mass flow rate, pressure and heat flux input. The two dimensional effectness isn’t very significant. The initial vapour film thickness doesn’t influence the wall temperature predictions very much.更多还原