Abstract
In this paper, effective thermal conductivities of water-based $Al_2O_3$-nanofluids with low concentration from 0.01 vol. % to 0.3 vol. % are experimentally obtained by transient hot wire method (THWM). The water-based $Al_2O_3$-nanofluids are manufactured by two-step method which is widely used. To examine suspension and dispersion characteristics of the water-based $Al_2O_3$-nanofluids, Zeta potential as well as transmission electron micrograph (TEM) is observed. We confirm the manufactured $Al_2O_3$-nanofluids have good suspension and dispersion. The effective thermal conductivities of the water-based $Al_2O_3$-nanofluids with low concentration are enhanced up to 1.64% compared with that of DI water at $21^{\circ}C$. In addition, experimental results are compared with theoretical results from Jang and Choi model.
