Investigation of Thermodynamic Properties and Stability of Metal Oxide (CuO and Al2O3)/Deionized Water Nanofluids for Enhanced Heat Transfer Applications

Abstract

The potential of nanofluids in improving heat transfer efficiency is well recognized, although there is a lack of clarity regarding the methods for assessing their stability and the influence on thermophysical properties. Moreover, the prevention of nanoparticle aggregation, which is essential for stability, requires further investigation. This study aims to address these issues by investigating the thermodynamic properties and stability of Al₂O₃/deionized water and CuO/deionized water nanofluids, which were prepared using magnetic stirring and ultrasonication. The stability assessment, conducted through standard deviation analysis, revealed that CuO (80 nm)/deionized water nanofluids exhibited greater stability compared to Al₂O₃ (80 nm)/deionized water nanofluids. The research explored the impact of temperature, volume concentration, and nanoparticle type under both static and dynamic conditions. Static tests focused on measuring thermal conductivity, viscosity, and specific heat, while dynamic tests involved a heat exchanger setup to determine heat transfer rates. The findings indicated that CuO nanofluids displayed the highest thermal conductivity and the most significant reduction in specific heat and heat transfer rate. Viscosity was found to increase with nanoparticle concentration and decrease with temperature. This study provides valuable insights into the thermophysical characteristics and stability of nanofluids, emphasizing the advantages of CuO-based nanofluids for heat transfer applications.