Abstract

Adding nanoparticles with high thermal conductivity into the work fluid is one of the most significant ways to enhance heat transfer. In this article, the influences of nanoparticle mass concentration (0.5–10.0 wt.%) and temperature (5–25 °C) were investigated on the viscosity of TiO₂-propylene glycol nanofluid. At the same time, eight kinds of mass concentrations (0.5–10.0 wt.%) were used to investigate the changing regularity on the surface tension of nanofluid; Accordingly, the modified correlations including nanoparticle concentration were proposed respectively. The experimental results show that the viscosity of the nanofluid increases with the increase in particle concentration. Within the concentration of 10.0 wt.%, the viscosity increases by about 7.0% for every 1.0 wt.%. While the viscosity decreases with the increase in the temperature. The surface tension of the mixture increases slowly with the increase in particle concentration. Within 2.0 wt.%, the surface tension of nanofluid increases by less than 1.0% for every 0.5 wt.%, when the concentration of nanofluid exceeds 2.0 wt.%, surface tension raises less than 1.0% per 2.0 wt.%.

摘要

将具有高导热性的纳米粒子添加到工作流体中是增强传热的最重要方法之一。_{在本文中，研究了纳米颗粒质量浓度（0.5–10.0 wt.%）和温度（5–25 °C）对 TiO 2}粘度的影响-丙二醇纳米流体。同时，采用8种质量浓度（0.5~10.0 wt.%）研究了纳米流体表面张力的变化规律；因此，分别提出了包括纳米颗粒浓度在内的修正相关性。实验结果表明，纳米流体的粘度随着颗粒浓度的增加而增加。在 10.0 wt.% 的浓度范围内，每增加 1.0 wt.%，粘度增加约 7.0%。而粘度随着温度的升高而降低。随着颗粒浓度的增加，混合物的表面张力缓慢增加。在2.0 wt.%以内，纳米流体的表面张力每增加0.5 wt.%，表面张力增加小于1.0%，当纳米流体浓度超过2.0 wt.%时，表面张力增加小于1。