Papers presented to the 11th International Conference on Heat Transfer, Fluid Mechanics and Thermodynamics, South Africa, 20-23 July 2015.
Nanofluids are new heat transfer fluid aimed at mitigating the
poor heat removal efficiency of the conventional heat transfer
fluids. Previous reports showed that nanofluids prepared from
conventional heat transfer fluids have higher thermal
conductivity compared to the constituent base fluids such as
water or ethylene glycol. However not much have been done in
other areas especially on the viscosity, electrical conductivity
and pH. In this paper, experimental investigations were carried
out on SiO2 nanoparticles dispersed in ethylene glycol at two
different energy densities using ultrasound assist mechanism.
The SiO2 nanoparticles used have an average particle size
(APS) 13.4±5.6 nm. The combined effect of temperature,
volume fraction and energy density on the viscosity, electrical
conductivity and pH of the nanofluids were investigated. The
temperature range investigated was between 20-70oC, volume
fraction between 0-5%, and energy density of 1.5105 kJ/m3
and 3.2105 kJ/m3. The results showed temperature and
volume fraction have significant influence on the viscosity,
electrical conductivity and pH of the nanofluids. However, the
energy density shows no significance on the viscosity of the
nanofluids which was dependent on the level of dispersion of
the suspension.
