棒束通道单相和两相交混模型评估

本研究利用子通道程序，基于已有的实验数据，对棒束通道的单相和两相交混模型进行了评估。单相交混主要考虑横流和湍流交混，横流由守恒方程决定并在流量分布中占主导作用，湍流交混取决于交混系数，对湍流交混研究发现Sadatomi模型预测结果与实验结果吻合较好。两相交混由横流、湍流交混和空泡漂移共同作用，通过已有模型预测结果与实验数据对比分析，推荐两相交混中空泡漂移采用Hotta模型、湍流交混系数采用Sadatomi模型和两相乘子采用Beus模型，这是一个预测结果较为保守的组合模型，有利于反应堆安全的保守性评估。 

Evaluation of Single-phase and Two-phase Mixing Models for Rod Bundle Channel

In this study, the subchannel program is used to evaluate the single-phase and two-phase mixing model of the rod bundle channel based on the existing experimental data. The single-phase mixing mainly considers the cross flow and turbulent mixing. The cross flow is determined by the conservation equation and plays a leading role in the flow distribution. The turbulent mixing depends on the mixing coefficient. It is found that the prediction results of Sadatomi model are in good agreement with the experimental results in the study of turbulent mixing. Two-phase mixing is jointly caused by cross flow, turbulent mixing and void drift. Through the comparative analysis of the prediction results of the existing models and the experimental data, it is recommended to use the Hotta model for the void drift in the two-phase mixing, the Sadatomi model for the turbulent mixing coefficient, and the Beus model for the two-phase multiplier. This is a combined model with conservative prediction results, which is conducive to the conservative evaluation of reactor safety.