Laminar convective heat transfer and pressure drop characteristics of Al₂O₃-water nanofluid were experimentally investigated inside a horizontal Helical-Coil Tube (HCT) under constant heat flux boundary conditions for Dean numbers between 400 and 1600. The experiments have been performed using Al₂O₃-water nanofluid of three mass concentrations and heat fluxes at different flow rates. Thermal conductivity and viscosity of the fluids are measured experimentally, and a proper agreement was observed with the new model predictions for thermo-physical properties of nanofluids. Based on the experimental results, the thermal conductivity and viscosity of Al₂O₃-water nanofluid were almost 2.12% and 3.1% higher than water in 1 wt% concentration. According to the observations, the heat transfer coefficients in the fully developed region increases by 6.4%, 19%, and 23.7% under 2283, 3774, and 4975 W/m² heat fluxes, respectively, at 1 wt% concentration of Al₂O₃-water nanofluid with respect to pure water. Besides, it has been noticed that pressure drop through the helical coil is increased with adding nanoparticles, enhancement of heat flux, and De number. Finally, based on the thermal performance factor, it has been concluded that using nanofluids in the helical coil is a feasible method for improving energy efficiency.

在恒定热通量边界条件下，对Dean数在400至1600之间的水平螺旋螺旋管（HCT）内，实验研究了Al ₂ O _3-水纳米流体的层流对流传热和压降特性。在不同流速下具有三个质量浓度和热通量的₂ O _3-水纳米流体。通过实验测量流体的热导率和粘度，并且观察到与新模型预测的纳米流体的热物理性质有适当的一致性。根据实验结果，Al ₂ O ₃的导热系数和粘度-水纳米流体在1 wt％的浓度下比水几乎高出2.12％和3.1％。根据观察结果，当Al ₂ O的浓度为1 wt％时，在2283、3774和4975 W / m ^2的热通量下，完全发达区域的传热系数分别增加6.4％，19％和23.7％。相对于纯水的₃水纳米流体。此外，已经注意到，通过添加纳米颗粒，增加热通量和De数，增加了通过螺旋线圈的压降。最后，基于热性能因子，可以得出结论，在螺旋线圈中使用纳米流体是提高能源效率的可行方法。