Wohld Jake, Beck Joshua, Inman Kallie, Palmer Michael, Cummings Marcus, Fulmer Ryan, Vafaei Saeid
Mechanical Engineering Department, Bradley University, Peoria, IL 61606, USA.
Nanomaterials (Basel). 2022 Aug 18;12(16):2847. doi: 10.3390/nano12162847.
The focus of this paper was to develop a comprehensive nanofluid thermal conductivity model that can be applied to nanofluids with any number of distinct nanoparticles for a given base fluid, concentration, temperature, particle material, and particle diameter. For the first time, this model permits a direct analytical comparison between nanofluids with a different number of distinct nanoparticles. It was observed that the model's average error was ~5.289% when compared with independent experimental data for hybrid nanofluids, which is lower than the average error of the best preexisting hybrid nanofluid model. Additionally, the effects of the operating temperature and nanoparticle concentration on the thermal conductivity and viscosity of nanofluids were investigated theoretically and experimentally. It was found that optimization of the operating conditions and characteristics of nanofluids is crucial to maximize the heat transfer coefficient in nanofluidics and microfluidics. Furthermore, the existing theoretical models to predict nanofluid thermal conductivity were discussed based on the main mechanisms of energy transfer, including Effective Medium Theory, Brownian motion, the nanolayer, aggregation, Molecular Dynamics simulations, and enhancement in hybrid nanofluids. The advantage and disadvantage of each model, as well as the level of accuracy of each model, were examined using independent experimental data.
本文的重点是开发一个全面的纳米流体热导率模型，该模型可应用于给定基础流体、浓度、温度、颗粒材料和粒径的含有任意数量不同纳米颗粒的纳米流体。该模型首次允许对含有不同数量不同纳米颗粒的纳米流体进行直接的分析比较。与混合纳米流体的独立实验数据相比，该模型的平均误差约为5.289%，低于现有的最佳混合纳米流体模型的平均误差。此外，从理论和实验两方面研究了操作温度和纳米颗粒浓度对纳米流体热导率和粘度的影响。结果发现，优化纳米流体的操作条件和特性对于最大化纳米流体和微流体中的传热系数至关重要。此外，基于能量传递的主要机制，包括有效介质理论、布朗运动、纳米层、团聚、分子动力学模拟以及混合纳米流体中的增强作用，讨论了现有的预测纳米流体热导率的理论模型。使用独立实验数据检验了每个模型的优缺点以及每个模型的准确性水平。
