湍流模型对5×5格架棒束通道流动传热数值模拟影响分析

CFD Evaluation of Turbulence Model on Heat Transfer in 5×5 Rod Bundles

同一软件工具采用不同湍流模型进行燃料组件格架棒束通道CFD分析时会得到不同的数值结果,本文采用ANSYS CFX软件,建立了包含典型5×5格架的棒束通道CFD模型,研究了涡粘和雷诺应力两大类6种典型湍流模型对燃料组件压降与换热特性数值结果的影响,计算了压降和Nu分布结果与相似的实验结果进行对比,通过分析3个典型搅混效果评价因子,探讨了搅混翼流动与换热的内在影响关系,同时对比了不同湍流模型对结果的影响。通过与相似实验数据对比分析,认为雷诺应力模型较适宜计算本文所研究的定位格架及棒束通道内流动传热特性。

Different turbulence models may lead to different results w hen analyzing fuel assemblies using computational fluid dynamics （CFD） method .In this paper ,a 5 × 5 rod bundle model was built to analyze the relationship between flow and heat transfer .The pressure drop and Nu were calculated using ANSYS CFX . Three factors evaluating swirling flow and cross-flow were used to analyze the inner relationship between flow field and heat transfer .T he performances of various turbulence models ,including eddy viscosity model and Reynold stress model ,were evaluated .The comparison between numerical and similar experimental results indicates that Reynold stress model is more appropriate for modeling flow features and heat transfer in spacer grids discussed in this paper .