Experimental and Comparative Study of Thermophysical Properties of Different Nanofluids with the Aim of Selecting the Best Nanolubricant

In this study, the effect of the ratio of different nanoparticle compositions on the viscosity performance of the base oil is investigated. The aim of this study is to achieve the characteristics of optimal nanolubricants. The experiments are performed at temperatures of 5-55°C, volume fractions of 0.05-1% and shear rates of 665.5-10664s-1. Experimental results showed that nanofluids have a non-Newtonian and quasi-plastic behavior. The maximum viscosity reductions are obtained for MWCNT / Al2O3 (10%: 90%) - 10W40 and MWCNT / Al2O3 (40%: 960%) - 10W40 at -8.13% and -10.85%, respectively. The results show that MWCNT / Al2O3 (10%: 90%)/10W40 nanofluids have better lubrication performance at engine start (lower oil viscosity) and engine movement (more controlled behavior) than competing nanofliud. Using the response level method, to predict the target response data, a normalized three-variable-three-degree model with the characteristics of the power transfer function, λ = -0.15 and a constant value equal to zero is presented. Margin of deviation is in the range of -"2.72" %<MOD<"2/66" %. More viscosity sensitivity also occurred at higher volume fractions.