CFD evaluation of turbulence models for flow simulation of the fuel rod bundle with a spacer assembly
CFD evaluation of turbulence models for flow simulation of the fuel rod bundle with a spacer assembly
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DOI：
10.1016/j.applthermaleng.2012.02.027
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发表时间：
2012-07
影响因子：
6.4
通讯作者：
C. C. Liu-C.;Y. Ferng;C. Shih
中科院分区：
文献类型：
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作者：
C. C. Liu-C.;Y. Ferng;C. Shih
计算流体动力学(CFD)越来越多地被用于核反应堆安全(NRS)分析，以更详细地描述反应堆冷却剂系统中发生的与安全相关的现象。本文给出了网格加密、壁面处理和边界条件的适当定义等对CFD模拟结果有很大影响的数值问题的结果。采用高质量的计算网格，研究了适用于棒束子通道内复杂旋流流动的湍流模型的选择。通过对燃料束中Nusselt数分布的计算，对各种湍流模型的性能进行了评价。没有近壁函数的湍流模型得到的Nusselt数的横向分布和轴向分布的数值结果与实验结果比较不是很好，而有近壁函数的Realizable k-epsilon模型的计算模拟与实验测量结果在靠近支撑网格的位置上是一致的。作为这项研究的结果，我们已经能够确定最合适的湍流模型和最好的增强型壁面处理来模拟反应堆冷却剂系统。
Computational fluid dynamics (CFD) is increasingly being used in nuclear reactor safety (NRS) analyses to describe safety-relevant phenomena occurring in the reactor coolant system in greater detail. This paper presents the results of numerical issues such as mesh refinement, wall treatment and appropriate definition of boundary conditions, which exert great influence on the results of a CFD simulation. A high quality computational mesh was used to investigate the choice of turbulence model appropriate for the complex swirling flow in the rod bundle subchannels. The performance of various turbulence models are evaluated by calculation of the Nusselt number distribution in a fuel bundle. Comparison between numerical and experimental results of lateral and axial distributions for the Nusselt number obtained via turbulence model without near-wall functions is not sufficiently good, while agreement is found between the computational simulation of the realizable k–epsilon model with near-wall functions and the experimental measurements, for locations close to the support grid. As a result of this study, we have been able to determine the most appropriate turbulence models and the best enhanced wall treatment for modeling reactor coolant systems.