Ting Hsien-Hung, Hou Shuhn-Shyurng
Department of Mechanical Engineering, Kun Shan University, Tainan 71070, Taiwan.
Materials (Basel). 2016 Jul 15;9(7):576. doi: 10.3390/ma9070576.
This study numerically investigates heat transfer augmentation using water-based Al₂O₃ and CuO nanofluids flowing in a triangular cross-sectional duct under constant heat flux in laminar flow conditions. The Al₂O₃/water nanofluids with different volume fractions (0.1%, 0.5%, 1%, 1.5%, and 2%) and CuO/water nanofluids with various volume fractions (0.05%, 0.16%, 0.36%, 0.5%, and 0.8%) are employed, and Reynolds numbers in the range of 700 to 1900 in a laminar flow are considered. The heat transfer rate becomes more remarkable when employing nanofluids. As compared with pure water, at a Peclet number of 7000, a 35% enhancement in the convective heat transfer coefficient, is obtained for an Al₂O₃/water nanofluid with 2% particle volume fraction; at the same Peclet number, a 41% enhancement in the convective heat transfer coefficient is achieved for a CuO/water nanofluid with 0.8% particle volume concentration. Heat transfer enhancement increases with increases in particle volume concentration and Peclet number. Moreover, the numerical results are found to be in good agreement with published experimental data.
本研究对层流条件下，在恒定热通量作用下，流经三角形横截面管道的水基Al₂O₃和CuO纳米流体强化传热进行了数值研究。采用了不同体积分数（0.1%、0.5%、1%、1.5%和2%）的Al₂O₃/水纳米流体以及不同体积分数（0.05%、0.16%、0.36%、0.5%和0.8%）的CuO/水纳米流体，并考虑了层流中700至1900范围内的雷诺数。使用纳米流体时，传热速率变得更加显著。与纯水相比，在佩克莱数为7000时，对于颗粒体积分数为2%的Al₂O₃/水纳米流体，对流换热系数提高了35%；在相同的佩克莱数下，对于颗粒体积浓度为0.8%的CuO/水纳米流体，对流换热系数提高了41%。传热强化随着颗粒体积浓度和佩克莱数的增加而增加。此外，发现数值结果与已发表的实验数据吻合良好。
