Influence of ethylene glycol - water mixture ratio on sio2 nanofluid turbulent forced convection heat transfer characteristics

Abstract

Experiments undertaken with SiO2 nanoparticles dispersed in ethylene glycol (EG) and water mixtures in the ratios of 60:40 and 40:60 by volume are reported in the literature for heat transfer and friction factor. The influence of concentration and temperature on heat transfer coefficient and friction factor have been determined. In this current study a theoretical model is developed to study the base fluid mixture ratios influence on heat transfer coefficient and flow characteristics in the turbulent range of Reynolds number employing the eddy diffusivity equation of van Driest. Two different base fluid mixture ratios of EG and Water mixed in 60:40 and 40:60 ratio by volume were considered for dispersing SiO2 nanoparticles. The property Enhancement Ratio of nanofluids for the two mixtures could depict the experimental observation of heat transfer enhancement. The temperature gradient is lower for EGW 40:60 mixture compared to 60:40 mixture. The Prandtl index decreases with an increase in nanofluid concentration and particle density. The numerical results indicate greater values of heat transfer coefficients with EGW of 40:60 mixture ratio compared to 60:40 ratio when plotted with velocity under identical conditions.