Pool boiling performance of aqueous Al2O3 and TiO2 nanofluids on a horizontally placed flat polished surface: an experimental investigation

Abstract

This paper presents an experimental investigation on the pool boiling heat transfer of water containing Al2O3 and TiO2 nanoparticles at 0.01%, 0.05%, 0.1%, 0.5% and 1% mass fractions at ambient pressure. A horizontal flat polished stainless steel plate was chosen as the boiling surface. Significant improvements in the boiling heat transfer coefficient and critical heat flux were recorded up to 0.1%. However, a decrease in heat transfer performance was observed at other concentrations. The surface wettability of nanofluids was improved as the static contact angle on the boiling surface decreased with an increase in mass fraction. The roughness of the boiling surface decreased due to the development of a layer of nanoparticles on it. Al2O3–water nanofluids showed better boiling performance than TiO2–water nanofluids. Finally, the present experimental outcomes are further compared and elucidated with the published reports and developed theories. This may be effective for a better understanding of pool boiling phenomena in nanofluids.