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本文对TiO_2-水,Cu水和SiO_2-水3种纳米流体在一种多孔小通道平行流扁管中的单相流动换热特性进行了实验研究。该扁管矩形通道水力直径1.67 mm,整个实验过程Re变化范围97~6200。实验结果表明:纳米流体起到强化换热效果的同时,也伴随着阻力的增加。此外,纳米流体相对于基液,出现了转捩提前现象。Nu随体积浓度的增加,先增加后减小,使得每种纳米流体都存在一个最优浓度。0.01%的TiO_2-水纳米流体在Re=6200时,Nu增长最大,达到43%。最后,利用性能评价标准对纳米流体的适用性进行了综合评定,0.01%的TiO_2-水纳米流体具有最佳性能。
In this paper, the single-phase heat transfer characteristics of three kinds of nanofluids TiO 2 -water, Cu water and SiO 2 -water in a multi-hole parallel-flow flat-flow tube were studied experimentally. The rectangular tube rectangular channel hydraulic diameter 1.67 mm, the entire experimental process Re range of 97 ~ 6200. The experimental results show that the nanofluid plays an important role in enhancing the heat transfer while increasing the resistance. In addition, nanofluids relative to the base fluid, there has been a turnaround advance phenomenon. With the increase of volume concentration, Nu first increases and then decreases, so that there is an optimal concentration for each nanofluid. 0.01% TiO 2 -water nanofluids at Re = 6200, Nu maximum growth, reaching 43%. Finally, the applicability of nanofluids was assessed by the performance evaluation criteria, and the best performance was obtained with 0.01% TiO 2 -water nanofluid.