Thermal performance of stable SiO2 nanofluids and regression correlations to estimate their thermophysical properties

• Published in: Journal of the Indian Chemical Society 2022-06, Vol.99 (6), p.100461, Article 100461
• Main Authors: Rajendra Prasad, T., Rama Krishna, K., Sharma, K.V., Naga Bhaskar, C.
• Format: Article
• Language: English
• Subjects: Glycerol-water; Nanofluid; Stability; Thermal conductivity; Viscosity; Zeta potential
• ISSN: 0019-4522
• DOI: 10.1016/j.jics.2022.100461

The present work investigates the best mix ratio of Glycerol in Water as a medium to prepare a stable nanofluid. Increasing the proportion of glycerol enhances the aqueous mix's dynamic viscosity and improves the prepared nanofluid's stability. The thermal conductivity and viscosity of the Glycerol and Water mixtures determination were undertaken at various Glycerol ratios. The best percentage of glycerol in the mixture is found to have the least amount of thermal conductivity loss and the optimum viscosity gain. Silica (SiO2) nanofluid of 0.25%, 0.5%, 1%, and 1.5% weight concentrations was prepared with this optimal mixture of Glycerol and Water. The stability of these SiO2 nanofluids is evaluated by determining the zeta potential at different time intervals. The nanofluids prepared were observed to be stable for one month. The thermal conductivity and viscosity of the nanofluids are measured between the temperature limits of 30°–70°C. A peak increment of 32.1%and 46.3% in thermal conductivity and viscosity is observed. Furthermore, when the percentage enhancement ratio (PER) and Mouromtseff ratio of these nanofluids is examined, it is observed that they have more excellent thermal performance at higher temperatures. Regression correlations are developed to estimate the thermal conductivity and viscosity of the prepared nanofluids with a maximum deviation of 9%. [Display omitted] •An optimum mixture ratio of glycerol water solutions was found as basefluid.•The stable silica nanofluids of various weight concentrations were prepared.•The prepared silica nanofluids were found to be stable for 30 days.•The thermal conductivity and viscosity of silica nanofluids are measured at different temperatures.•Regression equations are developed for estimating thermophysical properties of silica nanofluids.