M Kavosh - Department of Physics, islamic azad university,of masjedsoleyman branch, Islamic Republic of Iran
M Jahanbakhshi - Department of Chemistry, Islamic Azad University of masjed soleyman branch, Islamic Republic of Islamic Republic of Iran Iran

Nanofluids have great heat transfer properties more thre than typical fluids that causes they used in cooling systems and performance their efficiency. Heat transfer performance of nanofluid depends on viscosity, specific heat and density. Viscosity affects the pressure and the pumping power of fluids. when nanofluids are circulated in a closed loop for transfer of heat in cooling systems, they can affect the thermal conductivity due to phenomenon of convection. In this aper, an empirical viscocity assessment of CuO nanofluids based on Propylene Glycol (PG) has been carried out in different concentration and various temperatures of nanoparticles. For viscosity investigation of nanofluid, CuO NPs dispersed within propylene glycol (PG). The PG- based nanofluids with 0.3-2.3 vol. % CuO nanoparticles were perpared. viscosity measured by stabinger viscometer (SVM3000) in various temperatures such as 25'C, 40'C and 50'C. It seems that the sample with 0.3 vol% and 25'C has maximum viscosity and 1.9vol. %, 50'C shows minimum viscosity. It found that when CuO nanoparticles vol. % enhanced, a decrease in viscosity of propylene glycol-based nanofluids were showed. Increase in temperature caused reduced viscosity of Nanofluid. The viscosity results thus obtained are compared with predicts of Einstein's model.

nanofluids, propylene glycol, viscosity