Lin Lingnan, Kedzierski Mark A
National Institute of Standards and Technology, Gaithersburg, MD, USA.
Institute of Refrigeration and Cryogenics, Shanghai Jiao Tong University, Shanghai, China.
Int J Therm Sci. 2018;126 Pt B(Pt B). doi: 10.1016/j.ijheatmasstransfer.2018.06.077.
This paper presents specific heat measurements for a synthetic polyolester (POE) based aluminum oxide (AlO) nanolubricant with a polymeric surfactant over a temperature range from approximately 4 °C to 45 °C. AlO nanolubricants with two nominal surface-area-based diameter nanoparticles were investigated: 20 nm and 40 nm. The number-based diameter of the nanoparticles, as determined by dynamic light scattering (DLS), were 112 nm and 148 nm, respectively. The nanoparticle mass fractions were varied from 0.076 to 0.249 for the 112-nm diameter nanolubricant, and from 0.059 to 0.394 for the 148-nm diameter nanolubricant. The measurements showed that the specific heat of the nanolubricant linearly increased with increasing temperature, and linearly decreased with respect to increasing nanoparticle mass fraction. The size of the nanoparticle was shown to have no effect on the magnitude of the specific heat of the nanolubricant. The measurements were compared with two existing models. The mass fraction weighted model exhibited excellent agreement with the measurements (within ±1.01%). In contrast, the volume mass fraction model failed to predict the measurements for most conditions to within ±5%.
本文介绍了一种基于合成聚醇酯（POE）的氧化铝（AlO）纳米润滑剂在约4°C至45°C温度范围内添加聚合物表面活性剂后的比热测量结果。研究了两种基于标称表面积的直径纳米颗粒的AlO纳米润滑剂：20纳米和40纳米。通过动态光散射（DLS）测定的纳米颗粒的数量基准直径分别为112纳米和148纳米。对于直径为112纳米的纳米润滑剂，纳米颗粒质量分数在0.076至0.249之间变化，对于直径为148纳米的纳米润滑剂，纳米颗粒质量分数在0.059至0.394之间变化。测量结果表明，纳米润滑剂的比热随温度升高呈线性增加，随纳米颗粒质量分数增加呈线性下降。结果表明，纳米颗粒的尺寸对纳米润滑剂比热的大小没有影响。将测量结果与两个现有模型进行了比较。质量分数加权模型与测量结果表现出极好的一致性（在±1.01%以内）。相比之下，体积质量分数模型在大多数情况下无法将测量结果预测在±5%以内。
