Viscosity Analysis of MWCNT(25%)-ZnO(75%)/10W40 Hybrid Nanofluid; Toward a New Look at Finding Efficient Nanofluid for Heat Transfer Goals

In this study, viscosity of a 10W40-based engine oil containing MWCNT(25%) and ZnO(75%) was experimentally investigated. The experiments were carried out in a temperature range of 5-55 degrees C and different solid volume fractions (SVF) in the range of 0.05-1%. Viscosity measurements showed that this nanolubricant exhibits pseudo-plastic at all temperatures and VFs. Experimental data showed that in VF of 0.05%, the viscosity of nanofluid (NF) is lower than the viscosity of the base fluid. This finding shows that there is an optimal point for heat transfer applications in some hybrid NFs that makes them economical and optimal. Furthermore, a correlation is proposed to predict the dynamic viscosity. Also, the margin of deviation of this correlation in the prediction of viscosity was measured to be < 5%. To analyze the nanolubricant sensitivity, the sensitivity of the nano-oil was measured relative to the addition of a certain amount of nanoparticle (NP) to it. Based on the results, the sensitivity of the nanolubricant to concentration changes was higher than the effect of the temperature variation on it. The highest sensitivity is reported at SVF of 1% and the temperature of 55 degrees C.

Automated summary

In this study, the viscosity of a 10W40-based engine oil containing MWCNT and ZnO was experimentally investigated, showing pseudo-plastic behavior at all temperatures and solid volume fractions. The nanolubricant exhibited lower viscosity than the base fluid at certain conditions, indicating an optimal point for heat transfer applications. Sensitivity analysis revealed that the nanolubricant was more sensitive to concentration changes than temperature variations, with the highest sensitivity reported at SVF of 1% and temperature of 55 degrees C.