Abstract Reliable entrainment rate model is of great importance for the prediction of annular flow as it specifies the mass and momentum transfer between the liquid film and the droplet in the gas core. Various entrainment rate models have been proposed, yet few of them have a satisfying performance for a wide range of flow conditions, including gas/liquid phase flow rates, fluid type, channel size, etc. To develop a reliable entrainment rate model that is applicable to various fluids, instrumentation methods and available databases are reviewed in detail. The database for model development is determined by analyzing the instrumentation reliability and eliminating data points with the obvious error. The entrainment rate and the superficial liquid flow rate are nondimensionalized as Reynolds number using Laplace length as length scale, which is a critical wavelength of Taylor instability and related to the droplet size for annular flow. The entrainment rate model is developed based on the new nondimensional numbers, and the performance has been compared with various previous models. The evaluation results show that the prediction accuracy of the new model is better than previous models for a wide range of data.

中文翻译：

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一种新的环状两相流夹带率模型

摘要 可靠的夹带速率模型对环流的预测具有重要意义，因为它指定了气核中液膜和液滴之间的质量和动量传递。已经提出了各种夹带速率模型，但其中很少有在广泛的流动条件下具有令人满意的性能，包括气/液相流速、流体类型、通道尺寸等。 开发适用的可靠夹带速率模型对各种流体、仪器方法和可用数据库进行了详细审查。通过分析仪器可靠性，剔除有明显误差的数据点，确定模型开发的数据库。夹带速率和表面液体流速被无量纲化为雷诺数，使用拉普拉斯长度作为长度尺度，这是泰勒不稳定性的临界波长，与环形流的液滴尺寸有关。夹带率模型是基于新的无量纲数开发的，性能已经与之前的各种模型进行了比较。评估结果表明，新模型的预测精度优于以前的模型，适用于广泛的数据。