Convective Heat Transfer of Al2O3-water Nanofluids in a Microchannel Heat Sink

The research presents an experimental study on the heat transfer and pressure drop characteristics of Al2O3-water nanofluids flowing through a microchannel heat sink (MCHS). The effects of Reynolds number and particle concentrations on the heat transfer and flow behavior are investigated. Comparison of the heat transfer coefficient obtained from water-cooled MCHS and nanofluids-cooled MCHS is also presented. MCHS with rectangular flow channel made from aluminum with dimension of 50x50 mm is used as the test section. Al2O3-water nanofluids with particle concentrations of 1.0, 2.0 and 3.0 wt.% are tested. Two electric heaters each with a capacity of 50 W are used to supply heat to the test section. The results indicate that the heat transfer performance of MCHS increases with increasing Reynolds number as well as particle concentrations. Compared with pure water, the results indicate that at particle concentration of 3.0 wt%, the heat transfer coefficient for nanofluid-cooled MCHS is range between 1,100-1,700 W/m2K which is higher than that of water by about 7 – 15%. The pressure drop is between 8 and 25 kPa which is close to the water.