The sodium-cooled fast reactor (SFR), which is one of the most promising candidates for meeting the goal declared by the Generation IV International Forum (GIF), has drawn a lot of attention. Turbulent heat transfer in liquid sodium, which is a low-Prandtl fluid, is an extremely complex phenomenon. The limitations of the commonly used eddy diffusivity approach have become more evident when considering low-Prandtl fluids. The current study focuses on the assessment and optimization of the existing modeling closure for single-phase turbulence in liquid sodium based on reference results provided by the LES method. In this study, a wall-resolved Large-Eddy Simulation was performed to simulate the flow and heat transfer properties in a turbulent channel at low Prandtl number. The simulation results were first compared with the DNS results obtained from the literature. A good agreement demonstrated the capability of the employed numerical approach to predict the turbulent and heat transfer properties in a low-Prandtl number fluid. Consequently, new reference results were obtained for the typical Prandtl number and wall heat flux of an SFR. A time-averaged process was employed to evaluate the temperature profile quantitatively as well as the turbulent heat flux. Their dependency was also evaluated based on a systematic CFD simulation that covers the typical Reynolds numbers of SFRs. Based on the reference results obtained, the coefficients employed in an algebraic turbulent heat flux model (AFM) are calibrated. The optimized coefficients provide more accurate prediction of heat transfer properties for typical flow conditions of an SFR than the existing models found in the literature.

钠冷快堆（SFR）是实现第四代国际论坛（GIF）宣布的目标的最有希望的候选人之一，引起了很多关注。液态钠（一种低普朗特液体）中的湍流传热是一种极其复杂的现象。当考虑使用低普朗特流体时，常用的涡流扩散方法的局限性变得更加明显。本研究基于LES方法提供的参考结果，着重于评估和优化液态钠单相湍流现有建模闭包。在这项研究中，进行了壁解析大涡模拟，以模拟低普朗特数的湍流通道中的流动和传热特性。首先将仿真结果与从文献中获得的DNS结果进行比较。良好的协议证明了所采用的数值方法能够预测低普朗特数流体的湍流和传热特性。因此，获得了SFR的典型普朗特数和壁热通量的新参考结果。使用时间平均过程来定量评估温度曲线以及湍流。它们的依赖性也基于系统的CFD模拟进行了评估，该模拟涵盖了SFR的典型雷诺数。根据获得的参考结果，对代数湍流热通量模型（AFM）中采用的系数进行校准。