Experimental investigation on non-Newtonian behavior of Al 2 O 3-MWCNT/5W50 hybrid nano-lubricant affected by alterations of temperature, concentration and shear rate for engine applications

AuthorsMohammad Hemmat Esfe, Rostam Karimpour, Ali Akbar Abbasian Arani, Jalal Shahram
JournalINT COMMUN HEAT MASS
Presented byUniversity of Kashan
Page number97-102
Volume number82
Paper TypeFull Paper
Published At2017
Journal GradeISI
Journal TypeElectronic
Journal CountryIran, Islamic Republic Of

Abstract

In the present study, rheological behavior of Al2O3-MWCNT (65%–35%)/5W50 hybrid nano-lubricant is experimentally evaluated with the aim of facilitating its applications in automotive industry. Aluminum oxide (Al2O3) nanoparticles with the mean diameter of 50 nm along with multi-walled carbon nanotubes (MWCNTs) with inner diameter of 3–5 nm and outer diameter of 5–15 nm were used as nano-dispersants. Dynamic viscosity of samples of hybrid nano-lubricant composed out of 0% up to 1% solid volume fraction was measured at temperatures between 5 and 55 °C and shear rates between 666.5 and 10,664 s −1. As a result it was revealed that the hybrid nano-lubricant is a non-Newtonian fluid, also power law index signified shear thinning (pseudoplastic) behavior of the fluid. It was observed that increasing of solid volume fraction aggravates non-Newtonian behavior of the nano-lubricant; on the contrary, temperature increment had the reverse effect. For the purpose of forecasting viscosity of the hybrid nano-lubricant, a new correlation is proposed which is based on temperature and solid volume fraction. R-squared of the correlation outputs is 0.9923, this means that the correlation is capable of modeling viscosity behavior of the hybrid nano-lubricant.