Thermal and Hydrodynamic Characteristics of Graphite-H₂O and CuO-H₂O Nanofluids in Microchannel Heat Sinks

In this study, nanofluids were used as coolant for high-heat dissipation electronic devices with nanoparticle volume concentrations from 1% to 5%. The results were compared to other conventional cooling systems. Graphite-H2O and CuO-H2O nanofluids were analyzed at inlet velocities of 0.1 m/s and 1.5 m/s in a rectangular copper shaped microchannel heat sink MCHS with a bottom size of 20mm×20mm. The results indicate that suspended nanoparticles significantly increase thermal conductivity, heat flux, pumping power, and pressure drop. For graphite-water and CuO-water nanofluids at 0.1m/s with 5.0% volume, the greatest percentage increase in thermal conductivity was 15.52% and 14.34%, respectively. Graphite-water at 0.1 m/s and 1.5 m/s with 5% volume fraction had a maximum heat flux of 18% and 3.46%, respectively. CuO-water at 0.1 m/s and 1.5 m/s inlet velocity with the same volume concentrations had a heat flux of 17.83% and 3.33%, respectively. For graphite-H2O and CuO-H2O at 0.1 m/s with 5% volume fraction, pumping power and pressure drop were 0.000695 W and 92.63 Pa, respectively. For inlet velocity of 1.5 m/s with same volume concentration were 0.156306 W and 1389.39 Pa, respectively.