Thermal performance analysis of a microchannel heat sink cooling with copper oxide-indium (CuO/In) nano-suspensions at high-temperatures

An experimental investigation was conducted on the thermal performance and pressure drop of a microchannel heat sink under the low heat flux condition. Copper oxide nanoparticles (with the mean particle size of 50 nm) was dispersed in the liquid indium and experiments were conducted at 170 °C to avoid from solidification. The heat transfer coefficient, pressure drop and friction factor of the microchannel heat sink were experimentally measured at different mass concentrations of the liquid metal nanofluid and at different caloric temperatures. Results showed that with an increase in the applied heat flux to the microchannel, the higher heat transfer coefficient was achieved. In addition, with an increase in the peristaltic mass flow, higher heat transfer coefficient was registered. For the nanoparticle concentrations of up to 1%, no significant enhancement in the heat transfer coefficient was seen, however, for higher mass concentrations of up to 8%, the heat transfer coefficient increased and for the mass concentrations >8%, the heat transfer coefficient decreased. The correlations available in the literature have failed to estimate the Nusselt number for the CuO/In nanofluid, thereby using the regression analysis, a new correlation was proposed for the Nusselt number with a deviation of ±20%. A massive penalty in pressure drop was also registered for the liquid indium nanofluid at the mass concentration of 8% and higher.