Experimental investigation of heat transfer of Al2O3 nanofluid in a microchannel heat sink

Microchannel heat sink (MCHS) with nanofluids has been widely utilized to improve heat transfer performance in micro-scale mechanical systems. Although various studies have demonstrated the heat transfer phenomena of Al2O3 nanofluid in MCHS, the flow and heat transfer characteristics have not been fully elucidated due to a insufficiency of experimental results. To investigate these heat transfer phenomena, measurements of the temperature and velocity fields in the MCHS are important because the flow characteristics influence the heat transfer performance. Therefore, in the present study, velocity and temperature fields of Al2O3 nanofluid and deionized(DI) water in a MCHS were systematically analyzed by employing the particle image velocimetry(PIV) and laser induced fluorescence(LIF) measurement techniques. The heat transfer characteristics were explained using flow behaviors and temperature distribution in the MCHS. Moreover, the entropy generation rate in the MCHS was also evaluated to demonstrate heat transfer performance. When the nanofluid was used as a working fluid in the MCHS, the generation rate of thermal entropy was 6.3% smaller than that of water. In conclusion, we experimentally demonstrated the heat transfer of nanofluid by using the velocity and temperature measurement technique. The results of this study will advance the study of heat transfer using Al2O3 nanofluids. (c) 2021 Elsevier Ltd. All rights reserved.