A new generation of hybrid-nanofluid: thermal properties enriched lubricant fluids with controlled viscosity amount

The experimental rheological behavior study on Multi-Wall Carbon Nanotube (MWCNT)-TiO2 (40:60)/SAE50 hybrid nanofluid (NF) is the main subject of present work. The experiment conditions are temperature range of 25-50 degrees C and solids volume fractions of 0-1% at a shear rate (SR) range of 666.5-9331 s(-1). The results show that at an SR of 3999 S-1, the viscosity decreases by 76% when increasing the temperature at a concentration of 1%. Based on the results, NFs exhibit non-Newtonian behavior in all concentrations. Since the power-law index is less than 1 at all temperatures and volume fractions, its behavior is of pseudoplastic type. The results show that hybrid NFs at all solid volume fractions (SVFs) less than 0.5% has a viscosity lower than the base fluid. The sensitivity analysis and economic evaluation of using hybrid NFs are the other analyzed parameters in present study. The sensitivity analysis achieves its maximum value at SVF of 1% and the temperature of 50 degrees C, and its minimum value at SVF of 0.0625% and the temperature of 25 degrees C. In addition, to predict the viscosity of hybrid NFs, this study propose a three variable novel experimental model with a coefficient of determination (R-2) of 0.9882. Also investigation on hybrid NF effect on rheological behavior of NFs is another question in present study that is answered compeletely. [GRAPHICS] .