Heat transfer performance of jet impingement flow boiling using Al₂O₃-water nanofluid

An investigation is performed into the heat transfer performance of jet impingement flow boiling using Al₂O₃-water nanofluids with Al₂O₃ additions of 0, 0.0001, 0.001 and 0.01 vol%, respectively. It is shown that the heat transfer performance of jet impingement flow boiling using Al₂O₃-water nanofluid is poorer than that obtained when using de-ionized (DI) water as the working fluid. Scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS) observations reveal that the reduction in the heat transfer performance is due to the formation of a nano-sorption layer on the heated surface, which results in an increase in the thermal resistance. However, it is shown that by applying acoustic vibration to the heated surface, the formation of the nano-sorption layer is prevented; with the result that the heat transfer performance obtained using the Al₂O₃-water nanofluids is better than that obtained using pure DI water.