The viscosity behavior of ethylene glycol based titania/copper oxide nanofluids

Nanofluids are innovative heat transfer fluids engineered by dispersing metallic or non-metallic nanoparticles with typical sizes of less than 100 nm in conventional heat transfer fluids. Theproposed applications of nanofluids have generally been in the heat transfer area where a small concentration of particles often produces an-order-of-magnitude-larger heat transfer enhancement.In this work the rheological responces of ethylene glycol based titania/copper oxide nanofluids at0%, 0.5%, 3% and 10% wt (at equal concentration) were obtained at different particle concentration, temperature and shear rates. The viscosity of nanofluids was measured by arotational viscometer whiched equiped by a thermal bath over the shear rate range of 0.5 to 200 s-1 and temperature from 280 k to 340 k. The results show the Newtonian behavior over the wholerange of viscosity and temparature. The viscosity is affected strongly on particle concentration and temperature. For example, the viscosity increases from 21.5 mPa.s to 29 mPa.s at 40°C when 10% wt nanoparticles added to pure EG. The similar observation can be found for other concentration. Interestingly, the viscosity growth is independent of temperature and may be displayed by only a concentration-based equation. The increase of viscosity (normalized viscosity) can be well estimated by a power-law equation with constant factors

کلیدواژه ها:

Ethylene glycol ، Titania ، Viscosity ، Nanofluid ، Shear rate