Investigation of Thermodynamic Properties and Stability of Metal Oxide (CuO and Al 2 O 3 )/Deionized Water Nanofluids for Enhanced Heat Transfer Applications

Abstract

Abstract This research investigates nanofluids' thermodynamic properties and stability, specifically their potential to improve heat transfer in various applications. The study examines the methods used to characterise and measure the stability of two nanofluids: Al2O3/deionized water and CuO/deionized water nanofluids. These nanofluids are created using a two-step process involving magnetic stirring and ultrasonication. The stability of the nanofluids is evaluated quantitatively using standard deviation analysis, which reveals that CuO (80 nm)/deionized water nanofluids have better stability compared to Al2O3 (80 nm)/deionized water nanofluids. Additionally, the research explores how variables such as temperature, volume concentration, and nanoparticle type affect the properties of nanofluids under both static and dynamic conditions. In the static phase, the thermophysical properties of the fluids, including thermal conductivity, viscosity, and specific heat, are measured. In the dynamic phase, a setup resembling a heat exchanger is designed to determine the heat transfer rate. The study's findings show that CuO (80 nm)/deionised water nanofluids have the highest thermal conductivity compared to Al2O3 (80 nm)/deionised water nanofluids under the same conditions. Furthermore, viscosity tests demonstrate that increasing the volume concentration of nanoparticles increases viscosity while increasing temperature decreases viscosity. Lastly, the study reveals that CuO (80 nm)/deionized water nanofluids experience the greatest reduction in specific heat and heat transfer rate compared to Al2O3/deionized water nanofluids.