Abstract

In this study, mixed convection heat transfer of silver-water nanofluid was experimentally investigated under laminar flow regime inside a horizontal rectangular channel filled with an open-cell copper foam. Thermophysical properties of silver-water nanofluid at 1,000, 2,000, and 4,000 ppm concentrations were also measured. The morphological properties of copper foam were further measured by image processing. At the highest Reynolds number, metal-foam in the channel could increase the heat transfer coefficients of the top and bottom walls 1.6–3.7 times, respectively. Compared to deionized water, 15%, 20%, and 26% enhancement in heat transfer coefficients were achieved at nanofluid concentrations of 1,000, 2,000, and 4,000 ppm, respectively. The heat transfer coefficients of the top and bottom plates were increased by 4.7 and 2.7 time, respectively, at the highest Reynolds number and nanofluid concentration. Finally, two performance coefficients were proposed for the overall evaluation of the simultaneous application of porous-medium and nanofluid.

摘要

在这项研究中，在填充开孔泡沫铜的水平矩形通道内，在层流状态下，对银-水纳米流体的混合对流换热进行了实验研究。还测量了 1,000、2,000 和 4,000 ppm 浓度下银-水纳米流体的热物理特性。通过图像处理进一步测量了泡沫铜的形态特性。在最高雷诺数下，通道中的金属泡沫可使顶壁和底壁的传热系数分别增加 1.6-3.7 倍。与去离子水相比，在纳米流体浓度为 1,000、2,000 和 4,000 ppm 时，传热系数分别提高了 15%、20% 和 26%。顶板和底板的传热系数分别提高了 4.7 和 2.7 倍，在最高雷诺数和纳米流体浓度下。最后，提出了两个性能系数，用于综合评价多孔介质和纳米流体的同时应用。