Investigating the thermal properties of single-grade engine oil (SAE 50) with the simultaneous addition of MWCNT and CuO nanoparticles

Abstract

This study examines the MWCNT-CuO (20%–80%)/SAE50 nanofluid (NF) by considering the temperature changes, solid volume fraction (SVF), and shear rate (SR) parameters. The temperature range is 30–50 °C and SVF of 0.0625, 0.125, 0.25, 0.5, 0.75 and 1%, and different SRs are investigated. Viscosity is obtained using a Brookfield CAP 2000+ viscometer. The results show that the NF has a non-Newtonian behavior and the values of the power-law index are variable. Increasing the temperature of the NF decreases the viscosity because the intermolecular distance increases and the intermolecular forces decrease. Increasing the SVF in all SVFs except SVF = 0.0625 and 0.125% increases the viscosity, and therefore the SVF = 0.0625 and 0.125% have special importance. Modeling the viscosity of NF with the response surface methodology (RSM) has good accuracy so that the values of R2 and R2-adj are equal to 0.9993 and 0.9992, respectively. The sensitivity of NFs increases by adding 10% of the SVF in higher SVFs.