Rheological Behavior of SAE50 Oil-SnO₂-CeO₂ Hybrid Nanofluid: Experimental Investigation and Modeling Utilizing...

Area of Science:

• Materials Science
• Fluid Dynamics
• Nanotechnology

Background:

• Lubricant viscosity is critical for engine performance and efficiency.
• Developing advanced lubricants with tailored properties is essential for modern machinery.
• Hybrid nanofluids offer potential for enhanced thermophysical properties.

Purpose of the Study:

• To experimentally investigate the impact of temperature and nanopowder volume fraction (NPSVF) on the viscosity and rheological behavior of SAE50-SnO2-CeO2 hybrid nanofluid.
• To analyze the non-Newtonian characteristics of the nanofluid.
• To evaluate predictive models for dynamic viscosity.

Main Methods:

• Preparation of SAE50-SnO2-CeO2 hybrid nanofluids using a two-step method with NPSVFs from 0.25% to 1.5%.
• Experimental measurements of viscosity and shear stress at temperatures ranging from 25 to 67°C and shear rates from 1333 to 2932.6 s⁻¹.
• Application of Response Surface Method, curve fitting, ANFIS, and Gaussian Process Regression (GPR) for viscosity prediction.

Main Results:

• Shear stress increases with shear rate and decreases with temperature for both base fluid and nanofluid.
• A significant viscosity reduction of 89.36% was observed at 42°C with 1.5% NPSVF.
• Viscosity increased by 37.18% at 25°C with increasing NPSVF, exhibiting pseudo-plastic behavior across all conditions.
• Gaussian Process Regression (GPR) demonstrated superior performance in predicting dynamic viscosity compared to other models.

Conclusions:

• SAE50-SnO2-CeO2 hybrid nanofluid exhibits temperature-dependent viscosity and non-Newtonian pseudo-plastic behavior.
• Temperature significantly influences viscosity reduction, while NPSVF enhances viscosity.
• GPR is the most effective model for predicting the dynamic viscosity of this hybrid nanofluid.