thermo physical

Thermo physical properties of nanofluids The current study focuses the effect of oxidized multiwalled carbon nanotube dispersion in ethylene glycol–water mixtures on thermal conductivity and dynamic viscosity. The indirect assessment of heat transfer characteristics of the nanofluids is carried out from physico -thermal properties through Mouromtseff number (Mo). The base fluids comprise of all volume proportions of ethylene glycol - water combinations, with the volume percentage of ethylene glycol ranging from 100% to 0% for intended use in both for automotive and solar thermal applications. To achieve highest stability in EG-Water combinations, the MWCNTs are oxidised and dispersed in weight fractions of 0.05, 0.1, 0.25, and 0.5. For two months, the stability of nanofluids was assessed using UV-Vis spectroscopic analysis. There is a substantial surge in thermal conductivity of all samples in the range of 15 to 24 percent when MWCNTs are dispersed in the base fluids. A data set of 1500 points for all cases of temperatures, mass fractions, percentage of ethylene glycol is taken and correlations for thermal conductivity and dynamic viscosity have been proposed. After analysis of thermo-physical properties using Mouromtseff number (Mo), Dilute nanofluids with low concentration were shown to have the highest heat transfer capability under turbulent flow.纳米流体（nanofluids）热物理性质 本研究围绕氧化多壁碳纳米管在乙二醇-水混合溶剂中的分散行为，探究其对纳米流体导热系数与动力粘度的影响。本研究借助慕劳姆采夫数（Mouromtseff number, Mo），基于纳米流体的热物理性质间接表征其传热特性。基础流体涵盖乙二醇与水的全部体积配比组合，其中乙二醇体积占比范围为100%至0%，可满足汽车及太阳能热利用领域的应用需求。 为获得乙二醇-水混合体系下最优的分散稳定性，研究人员对多壁碳纳米管（multi-walled carbon nanotubes, MWCNTs）进行氧化改性，并以0.05、0.1、0.25及0.5的质量分数将其分散于基础流体中。采用紫外-可见分光光度法（UV-Vis spectroscopic analysis）对纳米流体的稳定性开展了为期两个月的监测评估。 当多壁碳纳米管分散于基础流体中时，所有样品的导热系数均实现15%至24%的显著提升。本数据集覆盖温度、纳米颗粒质量分数、乙二醇体积占比三类变量的全部工况，总计采集1500组有效数据点，并针对纳米流体的导热系数与动力粘度提出了相应预测关联式。借助慕劳姆采夫数（Mo）对纳米流体热物理性质进行分析后，结果显示低浓度稀纳米流体在湍流流动条件下具备最优的传热性能。