Experimental Investigation on the Viscosity of Nanofluids

In this study, the effect off adding SiO2 nanoparticles on the viscosity of base fluid is investigated experimentally. Base fluids are chosen among common heat transfer fluids such as ethylene glycol, transformer oil and water. In addition different volume percentages of ethylene glycol in water are used as ethylene glycol-water solution. In every base fluid different volume fractions of SiO2 nanoparticles is added. It is shown that the viscosity of solution enhance by adding nanoparticles. The effect of cooling and heating process on the viscosity of nanofluid is also discussed. The presented data show that as the temperature increases the viscosity of base fluid and nanofluid decrease. It is also revealed that there are very little differences between the viscosity of nanofluid in a specific temperature at cooling and heating cycles. According to the experimental results new correlations for predicting the viscosity of nanofluids is presented. These correlations relate the viscosity of nanofluid to the particle volume fraction and temperature.