Abstract In the present study, the flow and heat transfer of CuO-water nanofluid in different solid concentrations (1–4 vol%) in a tube have been simulated by using the single- and two-phase (mixture) models. The simulations have been conducted under the turbulent flow regime in different Reynolds numbers ranging from 3000 to 36,000. The effects of using CuO-water nanofluid on the Nusselt number, friction factor, and performance evaluation criterion have been investigated. It is found that employing the two-phase mixture model leads to having closer results in reality compared to the single-phase model. The results revealed that the maximum performance efficiency coefficient in the tube with one twisted tape is 2.18 (for the two-phase model, Re = 36,000 and φ = 4%), while for a tube with two twisted tapes under the same conditions, it is 2.04. Thus, the use of one twisted tape is more favorable from the thermal-fluid dynamics viewpoint.

中文翻译：

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扭带插件和纳米流体对管内流场和传热特性的影响

摘要 在本研究中，使用单相和两相（混合物）模型模拟​​了管中不同固体浓度（1-4 vol%）的 CuO-水纳米流体的流动和传热。模拟是在湍流状态下进行的，雷诺数从 3000 到 36,000 不等。研究了使用CuO-水纳米流体对努塞尔数、摩擦系数和性能评价标准的影响。发现与单相模型相比，采用两相混合模型在现实中得到更接近的结果。结果表明，带一根双绞带的管子的最大性能效率系数为 2.18（对于两相模型，Re = 36,000 和 φ = 4%），而在相同条件下，带两根双绞带的管子的最大性能效率系数为 2.18（对于两相模型，Re = 36,000 和 φ = 4%）是 2.04。