Sayantan MUKHERJEE, Paritosh CHAUDHURI, Purna Chandra MISHRA
Hybrid nanofluids are known for their attractive thermophysical properties and enhanced heat transfer potential. This study thoroughly investigates the impact of particle mixing ratios on the thermophysical and heat transfer characteristics of MgO-SiO2/water hybrid nanofluid. The mixing mass ratio (MR) of MgO:SiO2 was systematically altered including ratios of 100:0, 80:20, 60:40, 50:50, 40:60, 20:80, and 0:100 at a fixed particle concentration of 0.01% in volume. Experimental assessments of thermal conductivity and viscosity were conducted within the temperature range of 25°C–50°C at 5°C intervals. Thermal conductivity was measured by analysing sonic velocity of sound in nanofluid medium. Viscosity was determined by Ostwald viscosity apparatus. Sensitivity analysis was performed to examine the influence of mixing ratio and temperature on thermal conductivity and viscosity. Sustainability and economic analysis were conducted to guide future applications. The findings highlight the substantial influence of MR on thermal conductivity and viscosity enhancements within the hybrid nanofluid. The thermal conductivity exhibited a positive correlation with temperature elevation, with the hybrid nanofluid at MR=60:40 and 50°C displaying the highest thermal conductivity enhancement at 20.84% compared to water. In contrast, viscosity decreased with increasing temperature, with MR=50:50 at 50°C showing the maximum viscosity increase at 5.06% compared to water. New data-driven correlations for precise predictions of thermal conductivity and viscosity of hybrid nanofluid have been proposed. Sensitivity analysis revealed that mixing ratio had a more pronounced impact than temperature elevation. Sustainability and economic analysis concludes that MR=60:40 is an optimal, economical and sustainable choice for achieving peak heat transfer performance.