Abstract

The viscosity of MWCNT–Al₂O₃ (40–60)/5W50 hybrid nanofluid (NF) has been investigated. According to the results at different volume fractions (VFs) and temperatures, it possesses a behavior like non-Newtonian fluids. In this paper, we first compare MWCNT–Al₂O₃ (40–60%)/5W50 hybrid NF with MWCNT–Al₂O₃ (35–65%)/5W50 hybrid NF with focus on viscosity and cost performance index. Investigations were carried out for two shear rates (SR) of 3999 and 5332 (1/s). The decrease in viscosity at the SR of 3999 and in the VF of 1% at temperatures between 5 and 45 °C was 84%, and the SR of 5332 at 15 °C increased by 24%. Sensitivity was also studied, and at temperatures of 5–45 °C at a VF of 0.05%, this value was about 0.2%. This low viscosity sensitivity is very effective in improving the application of NFs in various engineering systems. A new empirical relation to anticipate the NF viscosity in accordance with the experimental results is also presented. The coefficient of determination (R²) for the mentioned relation is 0.9982, indicating the accuracy of the presented empirical relation to predict the NF viscosity at the tested temperature and concentration ranges.

Graphic abstract

中文翻译：

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MWCNT – Al 2 O 3（40–60％）/ 5W50杂化纳米流体的实验评估并与MWCNT – Al 2 O 3（35–65％）/ 5W50杂化纳米流体进行比较，重点是热物理性质和成本性能指标

摘要

研究了MWCNT-Al ₂ O ₃（40-60）/ 5W50杂化纳米流体（NF）的粘度。根据在不同体积分数（VF）和温度下的结果，它具有类似于非牛顿流体的行为。在本文中，我们首先将MWCNT-Al ₂ O ₃（40-60％）/ 5W50混合NF与MWCNT-Al ₂ O _{3进行比较。}（35-65％）/ 5W50混合NF，重点关注粘度和性价比指标。对3999和5332（1 / s）的两个剪切速率（SR）进行了研究。在5到45°C之间的温度下，在3999的SR和1％的VF下的粘度下降为84％，在15°C的5332的SR上升24％。还研究了灵敏度，在5-45°C的温度下，VF为0.05％，该值约为0.2％。这种低粘度敏感性对于改善NF在各种工程系统中的应用非常有效。还提出了一个新的经验关系，可以根据实验结果预测NF粘度。测定系数（R ²）的关系式为0.9982，表明所提供的经验关系式可准确预测被测温度和浓度范围内的NF粘度。

图形摘要