Experimental investigation of viscosity and specific heat of silicon dioxide nanofluids

Results of an experimental investigation into the viscosity and specific heat of silicon dioxide (SiO2) nanoparticles with various diameters (20, 50 and 100 nm) suspended in a 60: 40 (by weight) ethylene glycol and water mixture are presented. Nanofluids with particle volume percentages ranging from 0 to 10% were examined. Viscosity experiments were carried out over wide temperature ranges, from 235 to 50 degrees C, to demonstrate their applicability in cold regions. The nanoparticle diameter effect on the rheology of the SiO2 nanofluid is explored. Non- Newtonian behaviour was observed for the particle volume concentrations of these nanofluids at sub- zero temperatures. A new correlation was developed from experimental data, which related viscosity with particle volume percent and nanofluid temperature. The specific heats of the SiO2 nanofluids for various particle volume concentrations are presented.