Heat transfer enhancement using nanofluids (Al2O3-H2O) in mini-channel heatsinks

This paper presents the heat transfer enhancement characteristics using nanofluid Al2O3-H2O as a coolant in mini-channel heatsinks. Heatsinks with three different channel configuration were fabricated and tested for their heat transfer characteristics using nanofluids with two different volume concentrations and distilled water. Effects of channel configuration, coolant flow rate and volume concentration on the convective heat transfer coefficient, base temperature, thermal resistance, and heat transfer enhancement ratio have been reported. Moreover, the thermal and hydraulic performance of mini-channel heat sinks with four different channel configurations has been computed numerically using single phase and two-phase models. Computed results of convective heat transfer coefficient from both single and two-phase models were then compared with experimental results. Results revealed that the convective heat transfer coefficient enhances significantly by using nanofluids in comparison with distilled water. Moreover, predictions of two-phase mixture model were found in close agreement with an experimental model while single phase numerical model was found to have under predicted values of convective heat transfer coefficient.