Thermal conductivity and viscosity measurements of ethylene glycol-based Al2O3 nanofluids

Abstract

The dispersion and stability of nanofluids obtained by dispersing Al2O3 nanoparticles in ethylene glycol have been analyzed at several concentrations up to 25% in mass fraction. The thermal conductivity and viscosity were experimentally determined at temperatures ranging from 283.15 K to 323.15 K using an apparatus based on the hot-wire method and a rotational viscometer, respectively. It has been found that both thermal conductivity and viscosity increase with the concentration of nanoparticles, whereas when the temperature increases the viscosity diminishes and the thermal conductivity rises. Measured enhancements on thermal conductivity (up to 19%) compare well with literature values when available. New viscosity experimental data yield values more than twice larger than the base fluid. The influence of particle size on viscosity has been also studied, finding large differences that must be taken into account for any practical application. These experimental results were compared with some theoretical models, as those of Maxwell-Hamilton and Crosser for thermal conductivity and Krieger and Dougherty for viscosity.

Experimental investigation and model development for effective viscosity of MgO–ethylene glycol nanofluids by using dimensional analysis, FCM-ANFIS and GA-PNN techniques

“…This is a well-known procedure, to use rheology to characterise the state of dispersion of nanostructures in base fluids [14]. Programmable constant temperature thermal bath (LAUDA ECO RE1225) was used to vary the temperature of the samples Pastoriza-Gallego et al [23] within the present experimental uncertainty. A more detailed step-by-step experimental procedure can be found in Adio et al [24].…”

Dynamic Viscosity of Aluminum Oxide-Ethylene Glycol (Al₂O₃-EG) Nanofluids

“…This model has already been used to describe the dependence of viscosity on temperature by Pastoriza-Gallego et al for Al 2 O 3 EG [10] and ZnOEG [16] nanouids. For the Al 2 O 3 EG nanouids described in present paper, it was possible to t the VFT expression to the experimental data.…”

“…There are papers that describe the rheological properties of nanosuspensions of Al 2 O 3 , however, they are concentrated around the water-based nanouids [69]. Pastoriza-Gallego et al [10] presented the results of rheological studies, which show the dependence of the viscosity in Al 2 O 3 EG nanouids on particles sizes. Results acquired from our research complement these studies with the dynamic viscosity curves and conrm the idea, included in this study, that the temperature dependence of the viscosity of these materials can be described with the use of the VogelFulcherTammann (VFT) expression.…”

The Investigation of Effects of Temperature and Nanoparticles Volume Fraction on the Viscosity of Copper Oxide-ethylene Glycol Nanofluids

“…In Pastoriza-Gallego et al [28,29] study, the Newtonian behaviour of Al2O3/EG and ZnO/EG was obvious. Also, Żyła [30] and Mariano et al [31] investigated the viscosity of Y3Al5O12/EG and Co3O4/EG, respectively.…”