A novel study on rheological behavior of ZnO-MWCNT/10w40 nanofluid for automotive engines

In the present study, the effects of temperature, solid volume fraction and shear rate on viscosity of ZnO-MWCNT/10w40 hybrid nanolubricant is experimentally investigated. Zinc oxide nanoparticles and multi-walled carbon nanotubes with ratio of 55% to 45% respectively, were dispersed in engine oil, 10w40 type. Viscosity of the samples with solid volume fraction of 0.05 to 1% was measured at the temperatures between 5°C-55°C by Brookfield CAP 2000+ viscometer. The results indicate that the hybrid nanolubricant is shear-thinning non-Newtonian fluid. Power law index was reduced slightly as a result of increasing of solid volume fraction. On the other hand increasing of solid volume fraction was resulted in consistency index increment. A new correlation was proposed in terms of temperature and concentration. By using this correlation viscosity of the hybrid nanofluid can be predicted. This correlation has R2 = 0.9822 and it can predict viscosity of the oil-based nanofluid with acceptable error.