本文采用CFD方法对棒束内的流动状况进行非稳态模拟,利用已知的实验结果对计算模型进行验证,详细分析了非均匀壁面粗糙度条件下雷诺数对冷却剂交混流动特性的影响。结果表明:非均匀壁面粗糙度对棒柬间速度场分布及交混系数有明显的影响。并且,当流动雷诺数提高时,棒束间的交混强度先增强然后减弱,存在一个最佳的流动雷诺数条件,在此雷诺数下,非均匀壁面粗糙度棒束间的湍流交混和相干涡结构最强烈。 In this paper, CFD method was used to simulate the flow in the bundle, and the calculation model was verified by the known experimental results. The influence of Reynolds number on the cross-flow characteristics of the coolant was analyzed in detail. . The results show that the non-uniform wall roughness has a significant effect on the velocity field distribution and the mixing coefficient between rods and rods. Moreover, as the flow Reynolds number increases, the mixing intensities between the bundles first increase and then weaken, and there exists an optimal flow Reynolds number condition at which the turbulent mixing and coherence among the non-uniform wall roughness bundles Vortex structure is the most intense.