Effect of temperature and nanoparticle concentration on the viscosity of nanofluids

TiO2-water nanofluids with different concentration were prepared by the two-step method,and the stability were researched.The viscosities of nanofluids with various mass fraction of TiO2 nanoparticles were measured at 15-40℃.The results showed that the viscosity of the nanofluids increased with increasing nanoparticles concentration and diminished exponentially with increasing temperature.Besides,the variation trends of viscosity with temperature for all concentrations of nanofluids were similar.A new equation for calculating the nanofluids viscosity by considering particle concentration and temperature was proposed based on the experimental data,which corrected the previous equations and could well predict the experimental results of TiO2-water nanofluids.