Thermal conductivity measurement of methanol-based nanofluids with Al ₂O ₃ and SiO ₂ nanoparticles

In this study, the methanol-based nanofluids with Al ₂O ₃ and SiO ₂ nanoparticles are prepared by dispersing nanoparticles in pure methanol using an ultrasonic equipment. The main objective of this paper is to measure the thermal conductivity of the methanol-based nanofluids. We have also measured the zeta potential, particle size and Tyndall effect for the present nanofluids. The transient hot-wire method is applied for measuring the thermal conductivity of methanol-based nanofluids. The measurement uncertainty in repeatability is obtained as 1.95% for deionized (DI) water and 1.34% for pure methanol, respectively. The effective thermal conductivity of methanol-based nanofluids is measured at a temperature of 293.15 K. The results show that the thermal conductivity increases with an increase of the nanoparticle volume fraction, and the enhancement is observed to be 10.74% and 14.29% over the basefluid at the volume fraction of 0.5vol% for Al ₂O ₃ and SiO ₂ nanoparticles, respectively. Clustering of nanoparticles is considered to be the main reason for the thermal conductivity enhancement.