Dynamic viscosity of MWCNT/ZnO-engine oil hybrid nanofluid: An experimental investigation and new correlation in different temperatures and solid concentrations

The major objective of the present study was to investigate the dynamic viscosity of MWCNT/ZnO-engine oil hybrid nanofluid. The experiments carried out in different temperatures ranging from 5 degrees C to 55 degrees C and solid concentrations ranging from, 0.125% to 1%. The viscosity of the MWCNT/ZnO nanoparticle with the mean diameter of 30 nm dispersed in engine oil was measured using Brookfield cone and plate viscometer. The effect of temperature and solid concentration on dynamic viscosity of the nanofluid has been experimentally investigated. The results indicated that increasing the temperature resulted in decreasing the dynamic viscosity of the nanofluid by 85% while the dynamic viscosity increased as the solid concentration increased by 45%. Furthermore, based on the experimental data, a new model to predict the dynamic viscosity of the studied nanofluid has been proposed. (C) 2016 Elsevier Ltd. All rights reserved.