Experimental investigations were conducted to explore the thermal and exergy efficiency of Fe₃O₄‐H₂O nanofluids in a corrugated tube. Some influences of the twisted turbulator, horizontal magnetic fields (B = 6mT, 12mT, and 18mT), particle mass fractions (ω = 0.1, 0.3, and 0.5 wt%) as well as Re numbers (800–12,000) were analyzed. The experimental results exhibited that the heat transfer capacity of nanofluids intensifies with the increment of mass fraction but weakens with the increase of magnetic flux density. For the same external conditions, the heat transfer capability of the corrugated tube with an inserted twisted turbulator is obviously stronger than that without the turbulator. The resistance coefficient can be augmented by the increasing mass fraction and horizontal magnetic field. In addition, the thermal efficiency R3 and the exergy efficiency were adopted to estimate the comprehensive performance of each working condition. It could be found that the increased mass fraction and reduced magnetic flux density cause an increasing trend on the thermal efficiency. Also, it was obtained that the exergy efficiency of working fluids is intensified under identical pumping power.

中文翻译：

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磁场作用下流过内置扭曲湍流器波纹管的磁流体动力学Fe3O4-H2O纳米流体的热效率和火用效率

进行了实验研究，以探索波纹管中Fe ₃ O ₄ -H ₂ O纳米流体的热效率和火用效率。扭曲湍流器，水平磁场（B = 6mT，12mT和18mT），颗粒质量分数（ω = 0.1、0.3和0.5 wt％）以及Re的一些影响分析了数字（800-12,000）。实验结果表明，纳米流体的传热能力随着质量分数的增加而增强，但随着磁通密度的增加而减弱。在相同的外部条件下，插入扭曲式湍流器的波纹管的传热能力明显强于不带湍流器的波纹管。可以通过增加质量分数和水平磁场来增加电阻系数。另外，热效率R参照图3，采用火用效率估算每种工况的综合性能。可以发现，增加的质量分数和减小的磁通密度引起热效率的增加趋势。而且，获得了在相同的泵送功率下工作流体的（火用）效率得到增强。