Abstract Many boiling problems have been simulated by a phase change model (Lee model) involving an empirical mass transfer intensity factor. It is challenge to determine the value of this factor. An explicit expression of the mass transfer intensity factor is derived, and the accuracy of the expression is validated by comparing simulation results with theoretical solutions for two benchmark problems. The influences of various fluid properties (liquid phase density and thermal conductivity, latent heat, saturation temperature, vapor phase density and thermal conductivity) and mesh size on the mass transfer intensity factor are discussed. Results demonstrate that the mass transfer intensity factor depends on density and thermal conductivity of liquid phase, latent heat, saturation temperature and mesh size, but is independent of the density and thermal conductivity of vapor phase. Effects of vapor density and thermal conductivity on the phase interface movement are taken into account by the temperature of the interfacial cell. The expression reveals that a constant value of the mass transfer intensity factor throughout the computational domain is not reasonable, and which is the reason for divergence issue. In a specific computational cell, the value of the mass transfer intensity factor depends on the volume fraction of the liquid phase, and extremely large value of the factor should be consistent with extremely small volume fraction of the liquid phase.

中文翻译：

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广泛使用的相变模型中经验因子的显式表达

摘要 许多沸腾问题已经通过包含经验传质强度因子的相变模型（Lee 模型）进行了模拟。确定这个因素的价值是一个挑战。导出了传质强度因子的显式表达式，并通过将模拟结果与两个基准问题的理论解决方案进行比较来验证表达式的准确性。讨论了各种流体性质（液相密度和热导率、潜热、饱和温度、气相密度和热导率）和网格尺寸对传质强度因子的影响。结果表明，传质强度因子取决于液相的密度和热导率、潜热、饱和温度和网格尺寸，但与气相的密度和热导率无关。界面单元的温度考虑了蒸汽密度和热导率对相界面运动的影响。该表达式表明，整个计算域中传质强度因子的恒定值是不合理的，这就是发散问题的原因。在特定的计算单元中，传质强度因子的值取决于液相的体积分数，该因子的极大值应与极小的液相体积分数相一致。该表达式表明，整个计算域中传质强度因子的恒定值是不合理的，这就是发散问题的原因。在特定的计算单元中，传质强度因子的值取决于液相的体积分数，该因子的极大值应与极小的液相体积分数相一致。该表达式表明，整个计算域中传质强度因子的恒定值是不合理的，这就是发散问题的原因。在特定的计算单元中，传质强度因子的值取决于液相的体积分数，该因子的极大值应与极小的液相体积分数相一致。