An experimental report and new correlation for estimating the dynamic viscosity of MWCNT(50)-ZnO(50)/SAE 50 as nano-lubricant

In this study, the viscosity of SAE 50 engine oil containing MWCNT-ZnO nanoparticles was investigated experimentally. For this purpose, volume fractions (VFs) of 0.0625-1% of nano-oil were prepared and their dynamic viscosity was measured at different temperatures of 25-50 degrees C with changing shear rate (SR) and its rheological behavior was studied. The investigations showed the dependency of viscosity to SR variation, which is a sign for non-Newtonian behavior of nano-fluid (NF). The results clearly showed that pure oil and nano-oil behave non-Newtonian and behave similar to non-Newtonian shear-thinning fluids. To prevent spending extra money in future studies a new mathematical based correlation is proposed with the accuracy of R-2= 0.9984. By doing a comparisons between predicted resutls by the correlation and experimental results a proper accuracy in the mentioned temperature and concentration ranges was obtained.

Automated summary

This study experimentally investigated the viscosity and rheological behavior of SAE 50 engine oil containing MWCNT-ZnO nanoparticles. The results demonstrated non-Newtonian behavior in nano-oil, similar to non-Newtonian shear-thinning fluids. A new mathematical correlation was proposed to improve prediction accuracy and reduce costs in future studies.