Internal flows through rod assemblies are commonly found in heat exchangers, steam generators, and nuclear reactors. One of the fuel assembly designs considered for liquid metal-cooled reactors utilizes wires helically wrapped around each fuel rod as spacers. The wires keep the fuel pins separated, enhancing the turbulent mixing, and heat transfer, but also affecting the pressure drop. It is of interest the understanding of the fluid flow phenomena in the sodium-cooled fast reactor as it is one of the Generation IV advanced reactor designs and it has been a motivating topic of research for the last decade. A wire-wrapped fuel assembly replica with 61-pins has been in operation at the Thermal-Hydraulic Research Laboratory of Texas A&M University. This facility produced high-fidelity velocity and pressure drop data for validation of computational fluid dynamics codes. This study investigates the effects of geometrical features and operating conditions on the flow behavior of the 61-pin wire wrapped bundle using Reynolds-Averaged Navier-Stokes (RANS) models to predict the axial and transverse pressure drops for a range of Reynolds numbers from 1,270 to 100,000. The friction factor predictions were in satisfactory agreement with the experimental data and the Upgraded Chen and Todreas correlation. The internal subchannel velocity results were compared with experimental data and Large Eddy Simulations (LES) and found in reasonable agreement. This study demonstrates that RANS is a suitable approach in predicting velocity and pressure fields in wire-wrapped rod bundles, with a relatively low computational effort.

通过棒组件的内部流动常见于热交换器、蒸汽发生器和核反应堆中。考虑用于液态金属冷却反应堆的燃料组件设计之一利用螺旋缠绕在每个燃料棒周围的金属丝作为间隔物。电线使燃料棒保持分离，增强了湍流混合和传热，但也会影响压降。了解钠冷快堆中的流体流动现象很有趣，因为它是第四代先进反应堆设计之一，并且在过去十年中一直是研究的热点。具有 61 针的绕线燃料组件复制品已在德克萨斯 A&M 大学的热工水力研究实验室运行。该设施产生了用于验证计算流体动力学代码的高保真速度和压降数据。本研究使用雷诺平均纳维-斯托克斯 (RANS) 模型研究几何特征和操作条件对 61 针绕线束流动行为的影响，以预测从 1,270 起的一系列雷诺数的轴向和横向压降到 100,000。摩擦系数预测与实验数据和升级的 Chen 和 Todreas 相关性令人满意地一致。内部子通道速度结果与实验数据和大涡模拟 (LES) 进行了比较，发现具有合理的一致性。这项研究表明，RANS 是一种合适的方法来预测绕线杆束中的速度和压力场，