Influences of Temperature, Concentration and Shear Rate on Rheological Behavior of Nanofluid: An Experimental Study with Al2O3-MWCNT/10W40 Hybrid Nano-Lubricant

In this experimental study, the rheological behavior of Al2O3-MWCNT (90%:10%)/10W40 hybrid nano-lubricant has been determined at the temperature range of 5°C to 55°C. Al2O3 nanoparticles (average size of 50 nm) and MWCNTs (inner and outer diameter of 2-6 nm and 5-20 nm, respectively) were dispersed in engine oil (10W40) to prepare 0.05%, 0.1%, 0.25%, 0.5%, 0.75% and 1% solid volume fractions. For each sample, dynamic viscosity was measured at shear rates ranging from 666.5 s^-1 to 13330 s^-1 with an uncertainty of about 0.6%. The findings insinuated that at the most range of temperature and solid volume fraction the nano-lubricant, as well as the base oil, are non-Newtonian fluids. Thus, by curve fitting the indexes of power law and consistency were calculated. Eventually, the correlations indicated a very well compromise with experimental data