Thermal Conductivity Enhancement in Nanofluids for Heat Transfer Systems

Abstract

Efficient heat transfer is a critical requirement in modern thermal systems used in industries such as power generation, electronics cooling, automotive engineering, and renewable energy applications. Conventional heat transfer fluids such as water, ethylene glycol, and oils exhibit relatively low thermal conductivity, limiting system performance. Nanofluids, which are engineered by dispersing nano-sized particles into base fluids, have emerged as a promising solution for enhancing thermal conductivity and improving heat transfer efficiency. This study investigates the thermal conductivity enhancement behavior of nanofluids for heat transfer systems under varying operating conditions. The methodology involves the preparation of nanofluids using metal oxide nanoparticles such as Al₂O₃, CuO, and TiO₂ dispersed in base fluids at different volume concentrations. Ultrasonication techniques are used to ensure stable dispersion and prevent particle agglomeration. Thermal conductivity measurements are conducted using transient hot-wire and steady-state methods under different temperature and concentration conditions. The influence of particle size, concentration, and temperature on thermal performance is analyzed in detail. The results indicate that nanofluids exhibit significantly higher thermal conductivity compared to base fluids, with improvement increasing as nanoparticle concentration rises. It is also observed that smaller particle sizes and higher operating temperatures contribute to enhanced heat transfer performance. However, excessive particle loading may lead to stability issues and increased viscosity, affecting fluid flow characteristics.